Physical methods of dispersing characteristic use particles and compositions thereof

ABSTRACT

The present invention provides compositions that are capable of being dispersed in a target medium. The compositions include characteristic use particles entrapped within a physical entrapment phase, wherein the physical entrapment phase is dispersible in the target medium. Accordingly, the compositions of the present invention physically prevent the agglomeration or self-association of the characteristic use particles. Also disclosed are processes for manufacturing compositions that are capable of being dispersed in a target medium.

SPECIFICATION

This application is a division of U.S. patent application Ser. No.10/177,893 filed Jun. 21, 2002, which is a continuation-in-part of U.S.patent application Ser. No. 09/671,075 filed Sep. 27, 2000.

FIELD OF THE INVENTION

The present invention relates to a method of dispersing a characteristicuse particle in a target medium. In particular, the present inventionrelates to the use of a physical entrapment phase to preventagglomeration of the characteristic use particles.

BACKGROUND OF THE INVENTION

Small characteristic use particles, i.e., particles having an averagediameter of less than about 15 μm (microns), have been used in numerousapplications to impart certain desirable characteristics to a targetmedium. Target medium, as used herein, means any liquid, semi-solid orsolid medium to which the characteristic use particle is added.Characteristic use particle, as used herein, means a particle of amaterial that confers a desired benefit. For example, small amounts(e.g., about 1 to 2% by weight) of powdered or small particle sizepolytetrafluoroethylene (PTFE) have been incorporated in a variety ofcompositions to provide the following favorable and beneficialcharacteristics: (i) in inks, PTFE provides excellent mar and rubresistance characteristics; (ii) in cosmetics, PTFE provides a silkyfeel; (iii) in sunscreens, PTFE provides increased UV shielding or SPF(sun protection factor); (iv) in greases and oils, PTFE providessuperior lubrication; and (v) in coatings and thermoplastics, PTFEimproves abrasion resistance, chemical resistance, weather resistance,water resistance, and film hardness.

Without wanting to be limited by any one theory, it is believed thatthese small characteristic use particles are able to impart theirdesirable characteristics as a result of the unique chemical propertiesof the materials of which they are comprised. Unfortunately, those sameunique chemical properties typically cause the particles to agglomerateor self associate. Additionally, when the characteristic use particlesare placed in chemically distinct media, such as a hydrophobiccharacteristic use particle in a hydrophillic medium, agglomeration orself-association is well known to occur. Characteristic use particlesare, therefore, typically difficult to disperse and stabilize. Forexample, it is well known that PTFE is very difficult to disperse andstabilize (i.e., suspend) in target fluid systems (e.g., water, oils,solvents, coatings, and inks) and target semi-solid or solid systems(e.g., polymers, plastics, nylon). As a result, special chemicaladditives referred to as compatibilizing agents (e.g., surfactants,wetting agents, surface treating agents, etc.) are typically employed toassist dispersion and/or suspension of these particles in the targetfluid, semi-solid or solid system. In addition to added cost, thesecompatabilizing agents can cause deleterious effects or alter theperformance of the target system in which they are incorporated. Ingeneral, the compatibilizing agents are molecules having (i) at leastone portion that is a chemical group that strongly associates with, orthe surface of, a characteristic use particle and (ii) at least oneother portion that is a chemical group that associates with a targetmedium. They serve, therefore, to chemically alter the surfaceproperties of the characteristic use particle by forming an intermediaryphase between the self-associating material and the other chemicals inthe target medium, typically through complex chemical interactions, suchas covalent bonding, ionic interactions, hydrogen bonding, hydrophillicinteractions, hydrophobic interactions, van der Waals interactions andthe like. Thus, there is a need to develop new dispersion methods andcompositions to eliminate the need for these compatibilizing agents thatfunction via these complex chemical interactions.

It is, therefore, an object of the present invention to provide methodsand compositions, which disperse self-associating materials in a targetmedium using less than the typical amounts of compatibilizing agents forthe material being dispersed in the target medium. Thus, the instantcompositions and methods do not rely solely on chemical interactions inorder to prevent agglomeration.

SUMMARY OF THE INVENTION

The present invention provides compositions that are capable of beingdispersed in a target medium. These compositions include characteristicuse particles entrapped within a physical entrapment phase, wherein thephysical entrapment phase is dispersible in the target medium. As aresult, the compositions of the present invention physically prevent theagglomeration or self-association of the characteristic use particles.

In another embodiment, the present invention provides processes formanufacturing compositions that are capable of being dispersed in atarget medium. One process includes the steps of: mixing a precursorwith a characteristic use particle in a processing medium in which thephysical entrapment phase precursor is dispersible; converting theprecursor into a physical entrapment phase which is not dispersible insaid processing medium, thereby entrapping the characteristic useparticle within the physical entrapment phase; and separating thephysical entrapment phase from the processing medium to obtain saidcomposition. The product obtained according to this process is alsoencompassed by this invention.

In still another embodiment, the present invention provides a method ofconferring a desired benefit to a target medium. The method includes thestep of adding to a target medium a composition that is capable of beingdispersed in the target medium. The composition includes characteristicuse particles entrapped within a physical entrapment phase that isdispersible in the target medium, wherein the characteristic useparticles confer the desired benefit to the target medium.

In still another embodiment, the present invention provides compositionshaving a target medium, characteristic use particles dispersed withinthe target medium, and a physical entrapment phase dispersed within thetarget medium. For compositions with characteristic use particles havinga particle size of 2 microns or more, such compositions have a grindgauge improvement of greater than or equal to 1 unit in comparison tothe grind gauge for the composition without the physical entrapmentphase. For compositions with characteristic use particles having aparticle size of less than 2 microns, the Malvern method may be used toquantitate an increase in the dispersibility of the composition in thetarget medium of 10% or more, preferably 25% or more, or most preferably50% in comparison to the dispersibility of the composition in the targetmedium without the physical entrapment phase.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the present invention will be morefully appreciated from a reading of the detailed description whenconsidered with the accompanying drawings, wherein:

FIGS. 1A to 1C are illustrations of the phases obtained by mixingcharacteristic use particles with a precursor in a process medium;

FIGS. 2A to 2F are illustrations of the phases obtained when atriggering agent is added to process medium including characteristic useparticles and a precursor;

FIGS. 3A and 3B are photographs of polyethylene and polyethylenecontaining organoclay, respectively;

FIGS. 4A and 4B are photographs of PTFE dispersions in polyethylene;

FIGS. 5A and 5B are photographs of PTFE dispersions in polyethylene;

FIGS. 6A and 6B are photographs of PTFE dispersions in polyethylene;

FIGS. 7A and 7B are photographs of PTFE dispersions in mineral oil;

FIGS. 8A and 8B are photographs of PTFE dispersions in isopropylalcohol;

FIG. 9 is an illustration of the test tube used to determine thesettling rate for compositions formed according to the presentinvention;

FIGS. 10A and 10B are graphs of the ratio of the settling rate versusthe weight percent of organoclay;

FIGS. 11A to 11E are photographs of TiO₂ dispersions in mineral oil;

FIGS. 12A and 12B are Malvern results for pure powder submicron PTFE,wherein pure powder submicron PTFE was mixed with IPA and sonicated fortwo minutes and where IPA was used as a dispersant in the Malvernparticle size analyzer; FIG. 12B represents cumulative data; resultsindicate that the mean particle size value was 0.317 μm and that 97.89%of the PTFE particles were below 1.00 μm in particle size;

FIGS. 13A and 13B are Malvern results for 80% PTFE/20% organoclay,wherein the PTFE/organoclay powder was mixed with IPA and sonicated fortwo minutes and where IPA was used as a dispersant in the Malvernparticle size analyzer; FIG. 13B represents cumulative data; resultsindicate that the mean particle size value was 1.642 μm and that 72.74%of the particles were below 1.00 μm in particle size;

FIGS. 14A and 14B are Malvern results for submicron PTFE in IPA, whereinthe dispersion was diluted with IPA and sonicated for two minutes andwhere IPA was used as a dispersant in the Malvern particle sizeanalyzer; FIG. 14B represents cumulative data; results indicate that themean particle size value was 0.197 μm and that 100% of the particleswere below 1.00 μm in particle size;

FIGS. 15A and 15B are Malvern results for submicron PTFE in IPA/Quat,wherein the dispersion was diluted with IPA and sonicated for twominutes and where IPA was used as a dispersant in the Malvern particlesize analyzer; FIG. 15B represents cumulative data; results indicatethat the mean particle size value was 0.198 μm and that 100% of theparticles were below 1.00 μm in particle size;

FIG. 16 is a Malvern particle size distribution graph for PTFE in itsreactor latex form, where IPA was used as a dispersant in the Malvernparticle size analyzer;

FIG. 17 is a Malvern particle size distribution graph for reactor latexPTFE combined with bentonite clay slurry, where water was used as adispersant in the Malvern particle size analyzer;

FIG. 18 is a Malvern particle size distribution graph for reactor latexPTFE combined with warm dissolved Quat, where water was used as adispersant in the Malvern particle size analyzer;

FIG. 19 is a Malvern particle size distribution graph for 50/50organoclay/reactor latex PTFE having a clay/Quat ratio of 1:0.6, wheremineral oil was used as a dispersant in the Malvern particle sizeanalyzer;

FIG. 20 is a Malvern particle size distribution graph for 50/50organoclay/reactor latex PTFE having a clay/Quat ratio of 1:0.8, wheremineral oil was used as a dispersant in the Malvern particle sizeanalyzer;

FIG. 21 is a Malvern particle size distribution graph for 50/50organoclay/reactor latex PTFE having a clay/Quat ratio of 1:1.0, wheremineral oil was used as a dispersant in the Malvern particle sizeanalyzer;

FIG. 22 is a Malvern particle size distribution graph for 50/50organoclay/reactor latex PTFE having a clay/Quat ratio of 1:1.2, wheremineral oil was used as a dispersant in the Malvern particle sizeanalyzer;

FIG. 23 is a Malvern particle size distribution graph for 50/50organoclay/reactor latex PTFE having a clay/Quat ratio of 1:1.4, wheremineral oil was used as a dispersant in the Malvern particle sizeanalyzer;

FIG. 24 is a Malvern particle size distribution graph for 75/25organoclay/reactor latex PTFE, where IPA was used as a dispersant in theMalvern particle size analyzer;

FIG. 25 is a Malvern particle size distribution graph for 50/50organoclay/reactor latex PTFE, where IPA was used as a dispersant in theMalvern particle size analyzer;

FIG. 26 is a Malvern particle size distribution graph for 25/75organoclay/reactor latex PTFE, where IPA was used as a dispersant in theMalvern particle size analyzer;

FIG. 27 is a Malvern particle size distribution graph for 50/50organoclay/reactor latex PTFE that was irradiated at 7 megarads, wheremineral oil was used as a dispersant in the Malvern particle sizeanalyzer;

FIG. 28 is a Malvern particle size distribution graph for 50/50organoclay/reactor latex PTFE that was irradiated at 14 megarads, wheremineral oil was used as a dispersant in the Malvern particle sizeanalyzer; and

FIG. 29 is a Malvern particle size distribution graph for 50/50organoclay/reactor latex PTFE that was irradiated at 28 megarads, wheremineral oil was used as a dispersant in the Malvern particle sizeanalyzer.

DETAILED DESCRIPTION OF THE INVENTION

It has been surprisingly found that dispersion of particles of aself-associating material in a target medium can be significantlyimproved if the particles are occluded in a physical entrapment medium,wherein the physical entrapment medium is dispersible, or can be made tobe dispersible, in the target medium. The compositions of the presentinvention, therefore, are able to overcome the need for specialcompatabilizing agents, which rely solely on chemical interactions toprevent agglomeration in the target medium. The terms “disperse,”“dispersible” or “dispersion,” as used herein, mean that a referencedcomponent is finely divided or scattered within a medium. Preferably,the dispersed component does not phase separate into its own pure phasefor at least about 1 hour, more preferably for at least about one day,and most preferably for at least about one week after mixing thedispersible component in a target medium. Furthermore, when phaseseparation or settling of the dispersed component does occur, thesediment is “soft,” which means that the sediment may readily bere-dispersed by gentle agitation, e.g., shaking by hand.

Preferably, the compositions of the present invention have substantiallyless than the typically effective amount of compatabilizing agents forthe characteristic use particles in the target medium. The phrase“substantially less than the typically effective amount,” as usedherein, means that less than about 70%, preferably less than about 60%,and more preferably less than about 50% by weight of the referencedmaterial is present in the composition in comparison to the amounttypically used. The term “about,” as used herein, means ±10% of thestated value. For example, if the characteristic use material was DupontPTFE 30, a suspension of PTFE in water with surfactant, the surfactantcan also be included when Dupont PTFE 30 is occluded into a physicalentrapment phase. The amount of surfactant present in Dupont PTFE 30,however, would be substantially less than the typically effective amountof surfactant sufficient to disperse PTFE in a target medium.Furthermore, compatabilizing agents, which do not disperse thecharacteristic use particles in the target medium, can be present forany other component in the compositions of the present invention, e.g.,a compatibilizing agent for dispersing the physical entrapment phase inthe target medium. For example, such compatabilizing agents can be addedduring the manufacturing process of the characteristic use particle orthe physical entrapment phase, or can be used to fine tune theperformance of the inventive composition in the target medium.

The compositions of the present invention include characteristic useparticles and a physical entrapment phase that physically entraps thecharacteristic use particles, thereby physically preventing theagglomeration or self-association of the characteristic use particles.The physical entrapment phase is preferably dispersible in the targetmedium via normal mixing methods known in the art. The compositions ofthe present invention include from about 1.0% to about 99.0% by weight,preferably from about 2.5% to about 50% by weight, and more preferablyfrom about 5% to about 25% by weight of a physical entrapment phase; andinclude from about 99% to about 1.0% by weight, preferably from about92.5% to about 50% by weight, and more preferably from about 95% toabout 75% by weight of a characteristic use particle.

Because of the higher particle count for smaller characteristic useparticles (those having a particle size of less than 2 μm), thecompositions of the present invention also include from about 1% to 99%,more preferably from about 5% to about 75%, and most preferably fromabout 10% to 60% by weight of the physical entrapment phase; and includefrom about 99% to 1%, more preferably from about 95% to 25%, and mostpreferably from about 90% to 40% by weight of the characteristic useparticle.

These weight percentages do not include any compatabilizing agents orother ingredients, such as pigments, fillers, resins, etc., that may bepresent in the composition of the present invention. Typically, thecompositions of the present invention are dispersible in the targetmedium at a concentration of less than about 50%, preferably less thanabout 20%, and more preferably less than about 5.0% by weight of thetarget medium plus the instant composition.

The present invention is also directed to a target medium havingdispersed therein a physical entrapment phase and one or more types ofcharacteristic use particles. Target medium, as used herein, means anydesired liquid or solid medium into which the characteristic useparticles can be dispersed. As will be discussed in further detailbelow, the dispersibility of the physical entrapment phase in the targetmedium can be readily controlled. Thus, the physical entrapment phasecan be tailored to be dispersible in virtually any given hydrophobic orhydrophillic target medium. Hereinafter, hydrophobic can be referencedas “HB” and hydrophillic can be referenced as “HP.”

Nonlimiting examples of suitable hydrophobic target media (e.g., targetmedia having less than 1 gram solubility in 100 grams of water at roomtemperature) include: hydrocarbon-based compositions, such as motor oil,grease and mineral oil; solvents, such as aromatic solvents includingtoluene and benzene; unsaturated hydrocarbons, such as cyclohexane andpentachloroethylene; formamides; acetones of C₆ or higher carboncontent; alcohols having carbon chain lengths of C₅ or higher; resins;binders; fillers; film formers; coatings, such as paints, lacquers andclean coats; inks, such as flexogravure and heat set inks; plastics andpolymers, such as nylon, polystyrene, polyethylene, polypropylene,polyurethane, terephthalate, polyvinyl chloride, polyglycols, andcopolymers and terpolymers having any combination of the monomersthereof; chloro-, fluoro- and nitro-solvents; and mixtures thereof.

Nonlimiting examples of hydrophillic target media (e.g., target mediahaving greater than or equal to 1 gram solubility in 100 grams of water)include: water of neutral, acidic, or basic pH; linear and branched C₁to C₄ alcohols; C₁ to C₄ glycols; organic acids and their alkali metalsalts dissolved in water, such as acetic acid, formic acid, propionicacid, and butyric acid; ionic fluids containing water and water-solubleelectrolytes; C₁ to C₃ amines; low molecular weight organic sulfonicacids (both aromatic and aliphatic) and their salts; and mixturesthereof.

Characteristic use particles are made of a material that confers adesired benefit to a target medium. Typically these particles have anaverage diameter of less than about 15 μm (microns), preferably lessthan about 10 μm (microns), and more preferably less than about 5 μm(microns). Many characteristic use particles have a tendency toagglomerate or self-associate. Accordingly, when dispersed in a targetmedium, characteristic use particles, having a particle size of 2 μm ormore, in the compositions of the present invention (e.g., compositionsincorporating the characteristic use particle with a physical entrapmentphase) have a Hegman grind gauge improvement of greater than or equal toabout 1 unit, preferably greater than or equal to about 1.5 units, morepreferably greater than or equal to about 2.0 units, and most preferablygreater than or equal to about 2.5 units in comparison to the Hegmangrind gauge value of a dispersion of the characteristic use particles inthe target medium (e.g., without a physical entrapment phase). Furtherdetails regarding the Hegman grind gauge improvement are provided below.For compositions comprising characteristic use particles having aparticle size of less than 2 microns, the Malvern method may be used toquantitate an increase in the dispersibility of the composition in thetarget medium of 10% or more, preferably 25% or more, or most preferably50% in comparison to the dispersibility of the composition in the targetmedium without the physical entrapment phase.

Suitable characteristic use particles include, but are not limited to,polymers having one or more monomers, resins, binders, metal oxides,pigments, extenders, dyes, film forming agents, anticorrosive agents,matting/flattening agents, rheological modifiers, biocides, inorganicfillers, and flow modifiers. Further nonlimiting examples of suitablecharacteristic use particles include, polytetrafluoroethylene (PTFE),polyethylene (PE), polypropylene (PPE), polyethylene terephthalate(PET), polystyrene, polycarbonate, polymethyl methacrylates,polybutadiene, titanium dioxide (TiO₂), magnesium oxide (MgO), zincoxide (ZnO), ferrous oxide (FeO), ferric oxide (Fe₂O₃), calciumcarbonate (CaCO₃), lead chromate (PbCrO₄), barium sulfate (BaSO₄),molybdate orange, hansa yellow, phthalocyanine blue, phthalocyaninegreen, carbazole violet, carbon black, rubinine red, talc, china clay,mica, feldspar, and waxes. Preferred characteristic use particlesinclude PTFE, PE, PPE, TiO₂, carbon black, and CaCO₃.

Another specific example of a characteristic use particle that ispreferred in certain embodiments of the present invention is PTFE in itsreactor latex form. As used herein, the phrase “PTFE in its reactorlatex form” describes a suspension, in water, of PTFE particles in theirprimary particle size, that results from the synthesis of PTFE via anemulsion polymerization process. The primary particle size of PTFEparticles in samples of PTFE reactor latex is typically from about 0.1μm to about 0.5 μm. The term “latex” is commonly used in the art todescribe a water emulsion of a synthetic rubber or plastic obtained bypolymerization or a dispersion of polymerization products of rubber-likesubstances.

In embodiments where PTFE in its reactor latex form is used as thecharacteristic use particle, the reactor latex form of PTFE typicallycomprises from about 10% to about 40% by weight solid PTFE, withpreferred reactor latex PTFE samples comprising about 25% by weightsolid PTFE. PTFE in its reactor latex form is well known in the art tobe unstable and often spontaneously collapses or agglomerates with mildagitation, vibration or the like. Once PTFE in its reactor latex formhas collapsed, it is not readily dispersible. Thus, using PTFE in itsreactor latex form as a characteristic use particle in the presentinvention provides increased dispersibility in a target medium to thesolid PTFE particles via their being entrapped in a physical entrapmentphase.

Furthermore, in embodiments where PTFE in its reactor latex form is usedas the characteristic use particle, the resulting compositions(comprising reactor latex PTFE physically entrapped by a physicalentrapment phase, such as an organoclay) may be recovered, dried, andirradiated using electron beam irradiation and then dispersed in atarget medium. The irradiation may further enhance the dispersibility ofthe resulting reactor latex PTFE/organoclay compositions in varioustarget media. Typically in embodiments where the reactor latexPTFE/organoclay compositions are irradiated, the intensity of theirradiation ranges from about 5 to about 50 megarads, preferably fromabout 10 to about 40 megarads, and most preferably from about 20 toabout 30 megarads.

The compositions of the present invention also include a physicalentrapment phase, which prevents the agglomeration or self-associationof the characteristic use particles via a physical mechanism. Althoughthe physical entrapment phase preferably comprises particles that arereadily dispersible in the target medium, the physical entrapment phasecan also be a continuous phase that is readily dispersible in the targetmedium, such as a coascervate or gel. Without wanting to be limited byany one theory, it is believed that the physical entrapment particlesare of a sufficient numerical advantage to block or otherwise physicallyprevent agglomeration or self-association of the characteristic useparticles. Accordingly, it is preferred to have a number ratio ofphysical entrapment particles to characteristic use particles of greaterthan about 10:1, more preferably greater than about greater than about25:1, and most preferably greater than about 100:1.

Typically, the physical entrapment phase is obtained by mixing, by anyknown means or mechanism, a precursor of the physical entrapment phasewith the characteristic use particle in a process medium in which theprecursor is dispersible or soluble. The mode of incorporation can bemechanical in nature, such as stirring, and also can be any form ormethod of separating flocculates, agglomerates, or clumps of theparticles known to those skilled in the art of disperse systems.Nonlimiting examples include utilizing sonic energy, cavitation, thermalenergy, mechanical mixing, compatabilizing agents (e.g., surfactants)for the precursor and the process medium, and solubilization (e.g.,sugar or salts in water). Note that the mode of dispersion can includethe use of one or more compatibilizing agents, such as surfactants,which function through chemical interactions between the precursor andthe process medium. Such compatibilizing agents are distinguished fromthe compatibilizing agents that are typically used to disperse thecharacteristic use particles in the target medium.

Once the precursor is well dispersed or dissolved along with thecharacteristic use particles in the process medium, a triggeringmechanism is employed. The triggering mechanism converts the precursorinto the physical entrapment phase, so that the physical entrapmentphase is no longer dispersible or soluble in the process medium. Withoutwanting to be limited by any one theory, it is believed that thedispersibility of the precursor is caused to change quickly enough toentrap the characteristic use particles, which were mixed with theprecursor in the process medium. The resulting composition (or“composite”), which contains a mixture of the physical entrapment phaseand the characteristic use particles, is then separated by any knownmethod, such as filtration, centrifugation, evaporation, etc. Therecovered composite is then available for additional processing, such as(i) drying by any known means to remove all or part of the processmedium, and (ii) grinding or milling into a powder. Although therecovered composition can contain some of the processing medium, e.g.,water, it is preferred to obtain compositions that are substantiallyfree of the process medium, i.e., compositions having less than about10%, preferably less than about 5%, and most preferably less than about2.5% of the processing medium by weight of the recovered composition.Since the physical entrapment phase in the recovered composition isreadily dispersible, or can be made readily dispersible in a targetmedium, it is believed that the characteristic use particles are alsodispersed along with the physical entrapment phase in the target medium.

The physical entrapment phase can be formed by any known triggeringmechanism to change the dispersibility of the precursor in the processmedium, as long as the mechanism provides the following:

-   -   1. dispersibility of the precursor in the process medium;    -   2. a change in dispersibility of the precursor in the process        medium, which change in dispersibility can be triggered on        demand;    -   3. the resulting physical entrapment phase physically entraps        the characteristic use particles; and    -   4. the triggered physical entrapment phase can be dispersed, or        can be made to be disposed, into a target medium. The triggering        mechanism can include changing the reaction conditions (e.g.,        changing the temperature, pressure, volume, concentration of the        precursor, pH, and any combination of thereof), subjecting the        dispersed precursor to external stimuli, removing an external        stimuli, adding a triggering agent to react with the precursor,        and any combination thereof.

Examples of useful precursors include, but are not limited to,smectite-type clays (e.g., montmorillonite, bentonite, beidellite,hectorite, saponite, and stevensite) or organic cations, silicates,organic acids, colloidal salts, one reactant species used to formhydrous oxides that is soluble in the process medium (e.g., solublemetal salts), thixotropic agents, and pectin gels, such as Jello.Examples of useful triggering agents include, but are not limited to,organic cations for smectite-type clays or smectite-type clays fororganic cations to obtain organoclays; the other reactant of a hydrousoxide to obtain a hydrous oxide by hydrolysis or precipitation withalkali, alkali for water soluble silicates to obtain SiO₂ byprecipitation; metal salts for organic acids to obtain organic salts byprecipitation; acid or base for acrylic polymers to obtain acrylicpolymers by changing pH. Preferred physical entrapment phases obtainedby reacting a triggering agent with a precursor include organoclay andhydrous oxide.

Nonlimiting examples of triggering mechanisms include application of orchange in light, acoustics, temperature, pressure, volume of solvent,salt concentration, pH, electrolytic concentration, electromagneticwaves (e.g., microwaves, UV waves, and visible light waves),hydrophillicity (e.g., HP to HB), hydrophobicity (e.g., HB to HP),solubility (e.g., to cause precipitation), electricity, and combinationsthereof.

As discussed previously, the recovered composite can be furtherprocessed, e.g., dried and ground. In one embodiment of the presentinvention, the recovered composite (e.g., when containing hydrous metaloxides) can be further processed by reacting it with dilute acids orelectrolytes to provide peptization, i.e., the formation of a colloidalsolution or dispersion. Dilute acid, as used in this particularembodiment, means acid having a concentration of less than about 1N.Examples of suitable dilute acids include, but are not limited to:inorganic acids, such as sulfuric acid (H₂SO₄), hydrochloric acid (HCl),perchloric acid (HClO₄), and phosphoric acid (H₃PO₄); and organic acids,such as acetic acid (CH₃COOH), formic acid (HCOOH), propionic acid(CH₃CH₂COOH), butyric acid (CH₃CH₂CH₂COOH), chloroacetic acid(CH₂ClCOOH), dichloroacetic acid (CHCl₂COOH), and trichloroacetic acid(CCl₃COOH); and mixtures thereof.

Without the benefit of a physical entrapment phase, as shown in FIGS. 1Ato 1C, the characteristic use particle, e.g., white virgin PTFE powder,will agglomerate when mixed in the process medium, e.g., water. Whilemechanical energy or agitation is applied to overcome the highself-association energy of the PTFE, a highly hydrophillic fine particlesize material, such as bentonite clay, can be added as the precursor sothat the precursor and the PTFE are well dispersed in the process mediumin a high state of division. As a result, individual PTFE particles areseparated during agitation and are surrounded by many individualhydrophillic clay particles. At this point, if agitation isdiscontinued, the PTFE particles will phase separate due to their hightendency to self-associate, while the hydrophillic clay particles remaindispersed in the water.

In contrast, in one embodiment of the present invention, as illustratedin FIGS. 2A to 2F, agitation is continued and a triggering agent (e.g.,an organic cation) is added to the well-dispersed mixture of theprecursor, such as clay, and the PTFE particles in the process medium.The triggering agent reacts with or causes the precursor to becomehydrophobic (e.g., by ion exchange to form an organoclay), thus forminga hydrophobic physical entrapment phase. As a consequence, the highlydispersed, formerly hydrophillic precursor now agglomerates andphysically traps the PTFE in the agglomeration process.

The order of addition can be varied to some extent as long as the HBcharacteristic use particle and the HP precursor are both dispersedbefore triggering the HP to HB switch of the precursor. For example, theprecursor can be either the organic cation or the smectite-type clay.Thus, the HP precursor can be added to water or another processingmedium with agitation followed by the HB PTFE. Upon obtaining a gooddispersion by agitation or other methods, the triggering agent can beadded to change the HP precursor to the HB physical entrapment phase.For example, the triggering agent can be a smectite-type clay for anorganic cation precursor, or the triggering agent can be an organiccation for a smectite-type clay precursor. After the HP to HB transitionoccurs, the resulting coagulate can be recovered, dried and powdered.The PTFE is entrapped within the physical entrapment phase to form acomposite composition that can be incorporated and dispersed into atarget medium.

The physical entrapment phase is selected so that its chemicalcharacteristics are highly compatible with a target medium into which itcan be incorporated. Upon addition to the target medium, the physicalentrapment phase can readily disperse to provide a system having largenumbers of well dispersed particles. Without wanting to be limited byany one theory, it is believed that individual particles of PTFE areunable to agglomerate because each particle is surrounded by manyphysical entrapment particles that block reagglomeration. This mechanismof PTFE dispersion is achieved physically, and there is little or noneed for chemical compatibilizers, which modify the surface propertiesof the PTFE particles.

This technology can even be incorporated into the synthesis processesfor many characteristic use particles. For example, PTFE is usuallysynthesized in water, collected, and then dried. In accordance with thepresent invention, a hydrophillic precursor can be added to the aqueoussystem being used to form the PTFE at any step of the synthetic process.The hydrophillic precursor can, therefore, be present during theformation of the PTFE or added when the synthesis is completed. Forexample, a hydrophillic precursor such as a bentonite clay may be addedto PTFE in its reactor latex form following an emulsion polymerizationprocess of synthesizing PTFE. After synthesis of the PTFE is complete,the triggering mechanism (such as an organic cation) can be added and/oractivated to convert the hydrophillic precursor into a physicalentrapment phase. The resulting coagulate can then be collected anddried. This would result in a physically entrapped PTFE compositecomposition that is ready for use. Similarly, this would result in aphysically entrapped PTFE composite composition that may be irradiatedby electron beam irradiation and then used in the desired system ortarget medium.

This newly discovered process and compositions obtained therefrom arenot restricted to PTFE but can be applied to any characteristic usematerial that is not easily dispersible in the desired target medium.Nonlimiting examples of suitable materials that can be used for thecharacteristic use material have been provided above. For example,paraffin wax particles are difficult to disperse in many systems ofapplication, because paraffin wax particles are chemically incompatiblewith many chemicals. Once dispersed, they have a tendency toreagglomerate without the use of special chemical compatibilizingagents. The present invention avoids such dispersion and agglomerationdifficulties.

In one embodiment, smectite-type clays and in particular bentonite claycan be selected as the HP precursor. Bentonite clay is highlydispersible in water and results in numerous particles with an extremelyhigh surface area. On average, one can approximate a bentonite clayparticle in water as having the dimensions of 0.1 μm in length, 0.1 μmin width, and 10 Å in thickness. This clay also is well known to containexchangeable cations on its surface, which can be used to trigger the HPto HB transition. When dispersed in water, the surface exchangeablecations, such as Na⁺, Ca²⁺ and Mg²⁺, can be exchanged with organiccations, such as quaternary ammonium chlorides (“quats”), to form thewell known organoclays. The formation and use of organoclays aredescribed in U.S. Pat. No. 5,759,938 issued Jun. 2, 1998 to Cody et al.;U.S. Pat. No. 5,735,943 issued Apr. 7, 1998 to Cody et al.; U.S. Pat.No. 5,725,805 issued Mar. 10, 1998 to Kemnetz et al.; U.S. Pat. No.5,696,292 issued Dec. 9, 1997 to Cody et al.; U.S. Pat. No. 5,667,694issued Sep. 16, 1997 to Cody et al.; and U.S. Pat. No. 5,634,969 issuedJun. 3, 1997 to Cody et al.; and U.S. Pat. No. 4,664,820 issued May 12,1987 to Magauran et al.; which are all incorporated herein by referencein their entirety.

Also described in the above-referenced patents are additives which canbe employed to assist in organoclay dispersion. Examples of suitableadditives include, but are not limited to, polar activators, such asacetone; preactivators, such as 1,6 hexane diol; intercalates, such asorganic anions; and mixtures thereof. Such additives are also describedin U.S. Pat. No. 5,075,033 issued Dec. 24, 1991 to Cody et al.; U.S.Pat. No. 4,894,182 issued Jan. 16, 1990 to Cody et al.; and U.S. Pat.No. 4,742,098 issued May 3, 1988 to Finlayson et al.; which are allincorporated herein by reference in their entirety.

Organoclays may be prepared by reacting a certain type of clay with anorganic cation. Any clay, which can be reacted with one or more organiccations to provide a HP to HB change, can be used in the compositions ofthe present invention. Preferable clays are smectite-type clays having acationic exchange capacity of at least about 50 milliequivalents per 100grams of clay as determined by the well known ammonium acetate method orthe well known methylene blue method. The smectite-type clays are wellknown in the art and are available from a variety of sources. The clayscan also be converted to the sodium form if they are not already in thisform. This can conveniently be done by preparing an aqueous clay slurryand passing the slurry through a bed of cation exchange resin in thesodium form. Alternatively, the clay can be mixed with water and asoluble sodium compound, such as sodium carbonate, sodium hydroxide,etc., and the mixture sheared, such as with a pugmill or extruder.Conversion of the clay to the sodium form can be undertaken at any pointbefore reaction with the organic cation.

Smectite-type clays prepared synthetically by either a pneumatolytic or,preferably, a hydrothermal synthesis process can also be used to preparethese novel organic clay complexes. Representative of smectite-typeclays useful in the present invention include, but are not limited to,the following:

Montmorillonite having the general formula[(Al_(4−x)Mg_(x))Si₈O₂₀(OH)_(4−f)F_(f)]_(x)R⁺where 0.55≦x≦1.10, f≦4 and R is selected from the group consisting ofNa, Li, NH₄, and mixtures thereof;

Bentonite having the general formula[(Al_(4−x)Mg_(x))(Si_(8−y)Al_(y))O₂₀(OH)_(4−f)F_(f)]_((x+y))R⁺where 0<x<1.10, 0<y<1.10, 0.55≦(x+y)≦1.10, f≦4 and R is selected fromthe group consisting of Na, Li, NH₄ and mixtures thereof;

Beidel-lite having the general formula[(Al_(4+y))(Si_(8−x−y)Al_(x+y))O₂₀(OH)_(4−f)F_(f)]_(x)R⁺where 0.55≦x≦1.10, 0≦y≦0.44, f≦4 and R is selected from the groupconsisting of Na, Li, NH₄ and mixtures thereof;

Hectorite having the general formula[(Mg_(6−x)Li_(x))Si₈O₂₀(OH)_(4−f)F_(f)]_(x)R⁺where 0.57≦x≦1.15, f≦4 and R is selected from the group consisting ofNa, Li, NH₄, and mixtures thereof;

Saponite having the general formula[(Mg_(6−y)Al_(y))(Si_(8−x−y)Al_(x+y))O₂₀(OH)_(4−f)F_(f)]_(x)R⁺where 0.58≦x≦1.18, 0≦y≦0.66, f≦4 and R is selected from the groupconsisting of Na, Li, NH₄, and mixtures thereof, and

Stevensite having the general formula[(Mg_(6−x))Si₈O₂₀(OH)_(4−f)F_(f)]_(2x)R⁺where 0.28≦x≦0.57, f=4 and R is selected from the group consisting ofNa, Li, NH₄, and mixtures thereof.

The preferred clays used in the present invention are bentonite andhectorite, with bentonite being the most preferred. The clays may besynthesized hydrothermally by forming an aqueous reaction mixture in theform of a slurry containing mixed hydrous oxides or hydroxides of thedesired metals with or without, as the case may be, sodium (or alternateexchangeable cation or mixture thereof) fluoride in the proportionsdefined by the above formulas and the preselected values of x, y and ffor the particular synthetic smectite desired. The slurry is then placedin an autoclave and heated under autogenous pressure to a temperaturewithin the range of approximately 100° to 325° C., preferably 275° to300° C., for a sufficient period of time to form the desired product.Formulation times of 3 to 48 hours are typical at 300° C. depending onthe particular smectite-type clay being synthesized, and the optimumtime can readily be determined by pilot trials.

Representative hydrothermal processes for preparing syntheticsmectite-type clays are described in U.S. Pat. Nos. 3,252,757,3,586,478, 3,666,407, 3,671,190, 3,844,978, 3,844,979, 3,852,405 and3,855,147, all of which are herein incorporated by reference.

The organic cation which is reacted with the smectite-type clay musthave a positive charge localized on a single atom or on a small group ofatoms within the compound. The organic cation is preferably an ammoniumcation which contains at least one linear or branched, saturated orunsaturated alkyl group having 12 to 22 carbon atoms. The remaininggroups of the cation are chosen from (a) linear or branched alkyl groupshaving 1 to 22 carbon atoms; (b) aralkyl groups which are benzyl andsubstituted benzyl moieties including fused ring moieties having linearor branched 1 to 22 carbon atoms in the alkyl portion of the structure;(c) aryl groups such as phenyl and substituted phenyl including fusedring aromatic substituents; (d) beta, gamma-unsaturated groups havingsix or less carbon atoms or hydroxyalkyl groups having two to six carbonatoms; and (e) hydrogen.

The long chain alkyl radicals may be derived from natural occurring oilsincluding various vegetable oils, such as corn oil, coconut oil, soybeanoil, cottonseed oil, castor oil and the like, as well as various animaloils or fats such as tallow oil. The alkyl radicals may likewise bepetrochemically derived such as from alpha olefins.

Representative examples of useful branched, saturated radicals include12-methylstearyl and 12-ethylstearyl. Representative examples of usefulbranched, unsaturated radicals include 12-methyloleyl and 12-ethyloleyl.Representative examples of unbranches saturated radicals include lauryl;stearyl; tridecyl; myristyl (tetradecyl); pentadecyl; hexadecyl;hydrogenated tallow, docosanyl. Representative examples of unbranched,unsaturated and unsubstituted radicals include oleyl, linoleyl,linolenyl, soya and tallow.

Additional examples of aralkyl, that is benzyl and substituted benzylmoieties, would include those materials derived from, e.g., benzylhalides, benzhydryl halides, trityl halides, α-halo-α-phenylalkaneswherein the alkyl chain has from 1 to 22 carbon atoms, such as1-halo-1-phenylethane, 1-halo-1-phenyl propane, and1-halo-1-phenyloctadecane; substituted benzyl moieties, such as would bederived from ortho-, meta- and para-chlorobenzyl halides,para-methoxybenzyl halides, ortho-, meta- and para-nitrilobenzylhalides, and ortho-, meta- and para-alkylbenzyl halides wherein thealkyl chain contains from 1 to 22 carbon atoms; and fused ringbenzyl-type moieties, such as would be derived from2-halomethylnaphthalene, 9-halomethylanthracene and9-halomethylphenanthrene, wherein the halo group would be defined aschloro, bromo, iodo, or any other such group which serves as a leavinggroup in the nucleophilic attack of the benzyl type moiety such that thenucleophile replaces the leaving group on the benzyl type moiety.

Examples of aryl groups would include phenyl such as in N-alkyl andN,N-dialkyl anilines, wherein the alkyl groups contain between 1 and 22carbon atoms; ortho-, meta- and para-nitrophenyl, ortho-, meta- andpara-alkyl phenyl, wherein the alkyl group contains between 1 and 22carbon atoms, 2-, 3-, and 4-halophenyl wherein the halo group is definedas chloro, bromo, or iodo, and 2-, 3-, and 4-carboxyphenyl and estersthereof, where the alcohol of the ester is derived from an alkylalcohol, wherein the alkyl group contains between 1 and 22 carbon atoms,aryl such as a phenol, or aralkyl such as benzyl alcohols; fused ringaryl moieties such as naphthalene, anthracene, and phenanthrene.

The β,γ-unsaturated alkyl group may be selected from a wide range ofmaterials. These compounds may be cyclic or acyclic, unsubstituted orsubstituted with aliphatic radicals containing up to 3 carbon atoms suchthat the total number of aliphatic carbons in the β,γ-unsaturatedradical is 6 or less. The β,γ-unsaturated alkyl radical may besubstituted with an aromatic ring that likewise is conjugated with theunsaturation of the β,γ-moiety or the β,γ-radical is substituted withboth aliphatic radicals and aromatic rings.

Representative examples of cyclic β,γ-unsaturated alkyl groups include2-cyclohexenyl and 2-cyclopentenyl. Representative examples of acyclicβ,γ-unsaturated alkyl groups containing 6 or less carbon atoms includepropargyl; allyl(2-propenyl); crotyl(2-butenyl); 2-pentenyl; 2-hexenyl;3-methyl-2-butenyl; 3-methyl-2-pentenyl; 2,3-dimethyl-2-butenyl;1,1-dimethyl-2-propenyl; 1,2-dimethyl propenyl; 2,4-pentadienyl; and2,4-hexadienyl. Representative examples of acyclic-aromatic substitutedcompounds include cinnamyl(3-phenyl-2-propenyl); 2-phenyl-2-propenyl;and 3-(4-methoxyphenyl)-2-propenyl. Representative examples of aromaticand aliphatic substituted materials include 3-phenyl-2-cyclohexenyl;3-phenyl-2-cyclopentenyl; 1,1-dimethyl-3-phenyl-2-propenyl;1,1,2-trimethyl-3-phenyl-2-propenyl; 2,3-dimethyl-3-phenyl-2-propenyl;3,3-dimethyl-2-phenyl-2-propenyl; and 3-phenyl-2-butenyl.

The hydroxyalkyl group is selected from a hydroxyl substituted aliphaticradical wherein the hydroxyl is not substituted at the carbon adjacentto the positively charged atom, and the group has from 2 to 6 aliphaticcarbons. The alkyl group may be substituted with an aromatic ringindependently from the 2 to 6 aliphatic carbons. Representative examplesinclude 2-hydroxyethyl (ethanol); 3-hydroxypropyl; 4-hydroxypentyl;6-hydroxyhexyl; 2-hydroxypropyl (isopropanol); 2-hydroxybutyl;2-hydroxypentyl; 2-hydroxyhexyl; 2-hydroxycyclohexyl;3-hydroxycyclohexyl; 4-hydroxycyclohexyl; 2-hydroxycyclopentyl;3-hydroxycyclopentyl; 2-methyl-2-hydroxypropyl;1,1,2-trimethyl-2-hydroxypropyl; 2-phenyl-2-hydroxyethyl;3-methyl-2-hydroxybutyl; and 5-hydroxy-2-pentenyl.

The organic cation can thus be considered as having at least one of thefollowing formulae:

wherein X is nitrogen or phosphorus, Y is sulfur, R₁ is the long chainalkyl group, and R₂, R₃ and R₄ are representative of the other possiblegroups described above.

A preferred organic cation contains at least one linear or branched,saturated or unsaturated alkyl group having 12 to 22 carbon atoms and atleast one linear or branched, saturated or unsaturated alkyl grouphaving 1 to 12 carbon atoms. The preferred organic cation may alsocontain at least one aralkyl group having a linear or branched,saturated or unsaturated alkyl group having 1 to 12 carbons in the alkylportion. Mixtures of these cations may also be used.

Especially preferred organic cations include ammonium cations where R₁and R₂ are hydrogenated tallow and R₃ and R₄ are methyl or where R₁ ishydrogenated tallow, R₂ is benzyl and R₃ and R₄ are methyl or a mixturethereof such as 90% (equivalents) of the former and 10% (equivalents) ofthe latter.

The amount of organic cation reacted with the smectite-type clay dependsupon the specific clay and the desired degree of hydrophobicity.Typically, the amount of cation ranges from about 90 to about 150%,preferably from about 100 to about 130% and most preferably from about100 to about 116% of the cation exchange capacity of the clay. Thus, forexample, when bentonite is used, the amount of cation reacted with theclay will range from about 85 to about 143 milliequivalents, preferablyfrom about 95 to about 124 milliequivalents and most preferably fromabout 95 to about 110 milliequivalents per 100 grams of clay, 100%active basis. As is apparent to those of ordinary skill in the art, thecation exchange capacity of the clay is on the basis of the originalclay and is determined by the ammonium acetate method or the methyleneblue method. As is also apparent to those of ordinary skill in the art,other methods to obtain the cation exchange capacity include testingvarious ratios of organic cation to clay and identifying the ratio thatprovides the desired characteristics, e.g., a maximum amount oforganoclay dispersion in a selected target medium or a desired degree ofhydrophobicity.

The anion, which will normally accompany the organic cation, istypically one which will not adversely affect the reaction product orthe recovery of the same. Such anions may include, but are not limitedto, chloride, bromide, iodide, hydroxyl, nitrite and acetate in amountssufficient to neutralize the organic cation.

The preparation of the organic cationic salt (i.e., the organic cationpaired with the anion) can be achieved by techniques well known in theart. For example, when preparing a quaternary ammonium salt, one skilledin the art would prepare a dialkyl secondary amine, for example, by thehydrogenation of nitrites, see U.S. Pat. No. 2,355,356, and then formthe methyl dialkyl tertiary amine by reductive alkylation usingformaldehyde as a source of the methyl radical. According to proceduresset forth in U.S. Pat. Nos. 3,136,819 and 2,775,617, quaternary aminehalide may then be formed by adding benzyl chloride or benzyl bromide tothe tertiary amine. The contents of these three patents are herebyincorporated by reference in their entirety.

As is well known in the art, the reaction with benzyl chloride or benzylbromide can be completed by adding a minor amount of methylene chlorideto the reaction mixture so that a blend of products which arepredominantly benzyl substituted is obtained. This blend may then beused without further separation of components to prepare theorganophilic clay.

Illustrative of the numerous patents which describe organic cationicsalts, their manner of preparation and their use in the preparation oforganophilic clays are commonly assigned U.S. Pat. Nos. 2,966,506,4,081,496, 4,105,578, 4,116,866, 4,208,218, 4,391,637, 4,410,364,4,412,018, 4,434,075, 4,434,076, 4,450,095 and 4,517,112, the contentsof which are incorporated by reference.

In a typical organoclay/PTFE composition, virgin PTFE typically wouldhave a density of about 2.2 g/cc. One gram of PTFE occupies a volume ofabout 4.546×10⁻⁷ m³(1×10⁻⁶ m³+2.2). Since a particle of virgin PTFE hasan average diameter of about 3 μm (3×10⁻⁶ m), the volume occupied by anaverage PTFE particle is about 1.414×10⁻¹⁷ m³(volume=4/3πr³=4/3π(1.5×10⁻⁶ m)³). Thus one gram of PTFE contains about3.22×10¹⁰ particles (4.546×10⁻⁷ m³/g 1.41372×10⁻¹⁷ m³/PTFE particle).

Furthermore, in a typical organoclay/PTFE composition, the bentoniteclay would have a density of about 5 g/cc, and one gram of bentoniteclay occupies a volume of about 2.0×10⁻⁷ m³. Since an average singleplatelet of bentonite clay has the approximate dimensions of 0.1 μm×0.1μm×10⁻⁹ m, the volume occupied by an average single platelet ofbentonite clay is about 1.0×10⁻²³ m³ (volume=l×w×h=(1.0×10⁻⁷m)²×(1.0×10⁻⁹ m)). Thus, one gram of bentonite clay contains about2.0×10¹⁶ particles (2.0×10⁻⁷ m³/g−1.0×10⁻²³ m³/single plate).

Thus, for a typical PTFE particle of about 3 μm in diameter and adensity of about 2.2 grams per mL, the number of particles present in 1gram of PTFE powder will be approximately 3.2×10¹⁰ particles. Incomparison, using the dimensions of a bentonite clay platelet givenabove and assuming a density of about 5 grams per cc, 1 gram of claywill contain approximately 2×10¹⁶ particles. Thus, for a mixture of 1gram of clay with 1 gram of PTFE particles, there are approximately625,000 clay particles that can be converted to the HB physicalentrapment phase (e.g., as organoclay) per PTFE particle. Accordingly,in a dry coagulate composition (e.g., organoclay and PTFE), each PTFEparticle would be physically blocked from self-agglomeration withanother PTFE particle as each PTFE particle would be surrounded byapproximately 625,000 discrete organoclay particles.

Examination of the surface area relationship between PTFE and the HPprecursor (e.g., clay) that is switched to a HB physical entrapmentphase (e.g., organoclay) is equally instructive. Many bentonite claysare known to possess a surface area of several hundred meters squaredper gram, wherein the large surface area is maintained forwell-dispersed organoclay that is obtained from the bentonite clay. Incomparison, one gram of PTFE with an average particle diameter of about3 μm will have an approximate surface area of 1 meter squared.Therefore, each square meter of PTFE surface area is surrounded byhydrophobic particles having a surface area of several hundred squaremeters. Thus, the surface of each discreet PTFE particle would bephysically blocked from the surface of another PTFE particle by theorganoclay particles, thereby preventing self-association orself-agglomeration of the PTFE particles.

Organoclays based on smectite-type clays are the preferred physicalentrapment phase, since they are relatively inexpensive and can bereadily synthesized in forms that are easily dispersible into numeroushydrophobic target media. Numerous organic cations, such as quaternaryammonium compounds or “quats,” are commercially available for the HP toHB conversion of the clay, and these quats have distinct chemicalmoieties that can be tailored to accommodate the chemical properties ofa target medium. For example, tallow-based quats can be employed forhydrocarbon-based systems, whereas quats containing benzyl can be usedin target media including aromatic functional groups.

In another embodiment of the present invention, hydrous oxides can beutilized to form a physical entrapment phase that can be dispersed in ahydrophillic target medium. Hydrous oxides can be formed in water byprecipitation or hydrolysis of water soluble metal salts, therebyproviding a useful mechanism to entrap characteristic use particles. Therecovered mixture of hydrous oxide and characteristic use particles(“composition”) can then be peptized in water to form a highly dispersedcolloidal network surrounding the characteristic use particles.Peptization is the formation of a colloidal dispersion or sol. Colloidalsolutions or dispersions are intermediate in character between a truesolution and a suspension, wherein the dispersion has particles in thesize range of between about 1 μm and about 100 μm. The extremely smallcolloidal particle size provides a high numerical ratio of physicalentrapment phase to characteristic use particles. A wide variety ofhydrous oxides and the process of peptizing these hydrous oxides arewell known in the art, as described in Weiser, The Colloidal Salts,(McGraw-Hill Book Co., 1928) and Weiser, The Hydrous Oxides,(McGraw-Hill Book Co., 1926), both of which are incorporated herein byreference.

A nonlimiting example of a hydrous oxide is stannic oxide, which isreadily formed by the addition of alkali to SnCl₄ or SnBr₄. Hydrousstannic oxide can then be peptized by dilute mineral acids. Since thetarget medium is hydrophillic, e.g., water, after the precipitation istriggered the composite can be filtered. While containing water, thecomposite composition can be added to the target medium and peptized, orthe composite composition can be naturally peptized in an acidic targetmedium. It is not necessary to dry or grind the composition. Otherrepresentative examples of hydrous oxides include, but are not limitedto, SiO₂, TiO₂ and Al(OH)₃

When dispersed in a target medium, the compositions of the presentinvention (e.g., characteristic use particles, having a particle size of2 μm or more, entrapped in a physical entrapment phase) have a Hegmangrind gauge improvement of greater than or equal to about 1 unit,preferably greater than or equal to about 1.5 units, more preferablygreater than or equal to about 2.0 units, and most preferably greaterthan or equal to about 2.5 units in comparison to the Hegman grind gaugevalue of a dispersion of the characteristic use particles in the targetmedium (e.g., without a physical entrapment phase). For the grind gaugevalues obtained herein, two samples are prepared in the exact samemanner (e.g., same materials, apparatus, mixing settings, methods, etc.)except the control sample will include the characteristic use particlealone in the target medium and the test sample will include thecharacteristic use particles and the physical entrapment phase in thetarget medium.

The grind gauge test used herein is an adaptation of the Carlstadt TestMethod for Fineness of Grind Determination described in ASTM D1316-68,which was approved in 1968 and re-approved in 1979. Utilizing a Hegmangrind gauge, this test assesses the size and the prevalence of thelarger or coarser particles and agglomerates, but does not provideinformation on the average particle size of the powder. A Hegman grindgauge reading of 0 translates to a particle size of about 100 μm; areading of 1 translates to a particle size of about 85 μm; a reading of2 translates to a particle size of about 75 μm; a reading of 3translates to a particle size of about 62 μm; a reading of 4 translatesto a particle size of about 50 μm; a reading of 5 translates to aparticle size of about 37 μm; a reading of 6 translates to a particlesize of about 25 μm; a reading of 7 translates to a particle size ofabout 17 μm; and a reading of 8 translates to a particle size of lessthan about 2 μm. The procedure for the grind gauge test is as follows:

A calibrated Hegman production grind gauge with scraper (No. 440C at thebottom of the gauge; No. 5254 on the side of the gauge) is first cleanedwith a lint-free rag and an appropriate cleaning solution, such as butylcarbitol, IPA, or acetone. Approximately 0.2 grams of the test mixtureis then placed in both channels of the grind gauge. If the target mediumis a solid at room temperature, the test mixture can be heated to atemperature above the melting temperature of the target medium beforeapplying the test mixture onto the grind gauge, and the grind gauge canalso be heated to the same temperature. Grasping the scraper in bothhands in a nearly vertical position (e.g., the angle between the drawdown blade and the surface of the gauge should be between 80 and 90degrees), the sample is drawn down the gauge using a smooth, steadystroke that should take at least 3 seconds and no longer than 10seconds. Sufficient pressure is used so that the center and sideportions of the gauge are wiped clean.

The reading must be taken on the draw down within 10 to 20 seconds aftercompletion. The grind of the test sample is determined by examining thescratches and/or strays. Scratches are particles larger than thediameter of the film thickness. Strays are scratches that arenon-continuous. The grind gauge reading is the point at which three ormore scratches and/or strays are present. The procedure is repeated atleast twice, and the readings are averaged.

The compositions of the present invention also help to prevent theformation of or decrease the amount of clusters or agglomerates of thecharacteristic use particles. In other words, the entrapment of thecharacteristic use particles in the physical entrapment phase canimprove the free-flowing nature of the characteristic use particles.This desirable result can be directly measured by following tworeproducible methodologies to determine the decrease in the amount ofclusters and agglomerates provided by the compositions of the presentinvention: (i) a sieve test and (ii) a particle size analysis.

A sample of the compositions of the present invention, i.e.,characteristic use particles entrapped in a physical entrapment phase,has a 1 minute sieve weight % result of greater than or equal to about10%, preferably greater than about 20%, and most preferably greater thanabout 30% improvement in comparison to the 1 minute sieve weight %result of a sample of pure characteristic use particles (i.e., aspurchased commercially and without a physical entrapment phase).Similarly, a sample of the compositions of the present invention, i.e.,characteristic use particles entrapped in a physical entrapment phase,has an agglomerated particle size decrease of greater than or equal toabout 10%, preferably greater than about 20%, and most preferablygreater than about 30% in comparison to the agglomerated particle sizeresults of a sample of pure characteristic use particles. Theagglomerated particle size of the samples can be determined oninstrumentation, such as a Malvern Mastersizer 2000.

The first methodology performs a sieve test analysis for a fixed amountof a composition sample. The initial step includes making an estimate ofthe sieve size that would pass about 40% by weight of a control sample,i.e., a sample of pure characteristic use particles, in a 3 minute run.After thoroughly cleaning the sieve, about 3 to 5 grams of controlsample is placed onto the sieve, and both the control sample and thesieve are weighed. The sieve containing the control sample is thenplaced in a Micron Air Jet Sieve unit (commercially available fromMicron Powder Systems of Hosokawa Mircon Company located in Summit,N.J.) and covered with a plastic lid. The control sample is screened fora period of 180 seconds in manual mode while recording the vacuumpressure. Upon completion, the sieve and the remaining residue isweighed, and the weight percentage that passed through the sieve iscalculated.

If the weight percent passing through the sieve exceeds 45% or is below35%, the next appropriately sized sieve is selected, and the above stepsare repeated for the control sample. Once an appropriate sieve size isfound, i.e., a sieve size that allows from about 35% to about 45% byweight of the control sample to pass through the sieve, the above stepsare repeated using the sample. Additional data can be obtained byrecording the weight percent of the test sample passing through thesieve at 1, 2, and 3 minute intervals.

The second methodology includes the use of a computerized Malvernparticle size analyzer in which a small amount of the test sample isanalyzed, and the results can be compared to a control sample. A MalvernMastersizer 2000 dry unit, Scirocco 2000 Model #APA 2000, iscommercially available from Malvern Instruments Ltd., located inWorchestershire, United Kingdom. Both dry and wet samples can be tested.

For a dry sample, the procedure is as follows. First, both the feed trayand feed chamber are cleaned. Next, from about 2 to about 4 grams of thesample is loaded into the feed tray. After selecting the Dry PTFE SOP(Standard Operating Procedure) and entering the appropriate label oridentification information, analysis of the sample is initiated byright-clicking on the START icon. The Dry PTFE SOP is provided in theTable A below: TABLE A PTFE Dry SOP Criteria Setting Value SampleSelection Scirocco 2000(A) Material PTFE Refractive Index    1.38Absorption    0.1 Labels Factory Settings Reports & Saving FactorySettings Measurement Measurement Time 12 seconds Measurement Snaps12,000 Background Time 12 seconds Background Snaps 12,000 SamplerSettings Sample Tray General Purpose (<200 g) Dispersive Air Pressure 3Bar Aliquots Single Vibration Feed Rate 40% Measurement Cycle Single

Upon completion of the analysis, a graph representing the particle sizedistribution data and corresponding volume percent data can be obtainedby selecting the RECORDS tab, right-clicking to highlight the desiredrecord, and then selecting the RESULTS ANALYSIS (BU) tab.

For a wet sample (e.g., liquid a target medium containing the compositeor a liquid target medium containing the control), the procedure is asfollows. After selecting the Wet PTFE SOP, a manual measurement isinitiated by first selecting the OPTIONS icon. The Wet PTFE SOP isprovided below in Table B. TABLE B PTFE Wet SOP Criteria Setting ValueSample Selection Hydro 2000S(A) Material PTFE Refractive Index    1.38Absorption    0.1 Dispersant Name* Mineral Oil Refractive Index    1.4Labels Factory Settings Reports & Saving Factory Settings MeasurementMeasurement Time 12 seconds Measurement Snaps 12,000 Background Time 12seconds Background Snaps 12,000 Sampler Settings Pump/Stir Speed 2500RPM Tip Displacement 100% Ultrasonics Checked Pre-measurement 20 sec.Tank Fill Manual Cycles Aliquots Single Measurements 2 per AliquotCleaning Before each aliquot (check ENABLE) Clean Mode ManualMeasurement Cycle Multiple Delay 10 seconds*The dispersant name and its refractive index can be changed for aparticular dispersant used.

After entering the appropriate information (e.g., material underanalysis and the target medium in which it is dispersed), the liquidsample well is checked to ensure that it is empty. If the sample well isnot empty, it can be drained by right-clicking the EMPTY button on theACCESSORY menu. The empty liquid sample well is then cleaned by fillingit with Malvern's proprietary cleaning solution and initiating acleaning cycle by right-clicking the CLEAN icon. Next, the proper liquidis selected to flush the Hydro Unit. Using a pipette, the wet sample istransferred slowly into the sample well until the system prompts theuser to stop adding more of the sample and to initiate analysis.Analysis of the wet sample is initiated by right-clicking the STARTicon. Upon completion of the analysis, a graph representing the particlesize distribution data and corresponding volume percent data can beobtained by selecting the RECORDS tab, right-clicking to highlight thedesired record, and then selecting the RESULTS ANALYSIS (BU) tab.

As mentioned earlier, one of the preferred characteristic use particlesused in the present invention is PTFE. Embodiments described abovecontemplate the use of PTFE powder or PTFE in its reactor latex form asa characteristic use particle that benefits from the present invention.Since PTFE is useful in so many applications, compositions resultingfrom the present invention, comprising small particle size PTFE as thecharacteristic use particle entrapped in a physical entrapment phase,will be equally as useful in many applications, some of which are listedbelow in Table C: TABLE C Applications for Compositions with SmallParticle Size PTFE as the Characteristic Use Particle BENEFITS SOUGHTAPPLICATION Film or Coating Auto Topcoat Transparency Optical FibersTextile Fibers UV Packing Clear UV Protection of Wood Rub/ScratchResistance Ink Ink Jet Toners Can Coatings Auto Topcoat ThermoplasticsUV Packing Feel, Texture Textile Fibers Thermoplastics Cosmetics ThinFilms UV Resistance Cosmetics (SPF) Clear Coat for Wood Marine CoatingsAutoTopcoat Textile Fibers (Clothing, Rugs, etc.) Weather/ChemicalResistance Electronics (Water, Water Vapor) Oxidation Resistance MarinePaint (Antifoullant) Chemical Storage and Reaction Tanks Can Coating(Food) Wood Treatment Lubrication Auto Motor Oils Gear LubricantsBearings, Shick 50 Bowling Alleys Thermoplastics (Processing Aid) MoldRelease Fiber Manufacturing

The above-listed benefits and applications for compositions comprisingPTFE as the characteristic use particle are not exhaustive, as manyother applications and benefits for PTFE exist. The PTFE-containingcompositions formed in the present invention may be dispersed directlyinto the target media or application systems listed above, or may bepre-dispersed into a carrier liquid and then placed in the target mediumor system of use.

EXAMPLES

These examples further describe and demonstrate embodiments within thescope of the present invention. The examples are given solely for thepurpose of illustration and are not to be construed as limitations ofthe present invention, as many variations thereof are possible withoutdeparting from the spirit and scope of the invention.

The following common ingredients were used in the Examples below, unlessotherwise specified: Ingredient Company Polytetrafluoroethylene (PTFE)SST3D or Shamrock Technologies, Inc. SST4¹ Polyethylene S-395-N1Shamrock Technologies, Inc. Quat: Adogen 442-100 P or 442-75 WitcoCorporation (dimethyl dihydrogenated tallow quaternary ammonium)Bentonite Clay - National Premium Bentonite Corporation Weight 200 meshIsopropyl Alcohol N/A Klearol (mineral oil) Witco Corporation AcetoneNovick Chemical Co., Inc. Tap Water N/A¹The Shamrock Technologies data sheet describes SST-4 as an off-whitefree-flowing PTFE powder, wherein the PTFE particles have an averagediameter of 4 microns, a specific gravity of about 2.15, an onset ofmelting at about 200° C., and a crystalline point of 321° C. SST-3D is awhite free-flowing PTFE powder, wherein the PTFE particles# have an average diameter of 5 microns, a specific gravity of about2.15, an onset of melting at about 200° C., and a crystalline point of321° C.

In addition, unless otherwise specified, the following instruments wereused in the Examples described below: Instrument Company & SpecificationConditions Magnetic Plate Corning Stirrer; Range 0-9 Set at variousspeeds and durations of time. Blender, 1L Waring Company; Model No. Setat various speeds and durations 3413297 of time. IEC SpinnetteLaboratory Damon/IEG Division, Needham, 5 minutes at maximum speed.Centrifuge MA Hegman Grind Gauge (Fineness of Precision Gage & Tool.Co., H: 0-8 Grind Gauge) Dayton, OH MLS: 4-0 μ: 100-0 N.P.I.R.I.Production Grindometer Precision Gage & Tool. Co., NPIRI: 0-10 GrindGauge Dayton, OH μ: 0-25 Horizontal Media Mill: Eiger Machinery, Inc.Set at 2600 RPM for 4 passes. Mini Motormill 100 Grinding MachineScienceware Bel Art Product 2 minutes at fixed speed. Mixer MagnetekCompany; CAT No. ˜1000 RPM D552 Microscope (Color video Sony Corporation170/−10/0.25 P camera/CCD-Iris) Serial No. 10368 Model No. DXC-960MDHR-202 Scale 1 AND Company N/A Max 210 g, d = 0.1 mg FX 320 Scale 2 Max310 g, d = 0.01 g N/A

Example 1 Dispersion of PTFE and PTFE/Organoclay in Organic Solvents

250 mL of hot tap water at 60° C. was placed in a Waring Blender. Whilemixing at a setting of 6, 10 grams of PTFE (Grade SST 4) was slowlyadded and mixed for about 5 minutes. Three grams of quat (methyl benzyldehydrogenated tallow ammonium chloride, sold under the tradenameKemamine BQ-9701C by Witco Corp.) was slowly added to the water/PTFEmixture and mixed for about 5 minutes. Then, 4.23 grams of hectoriteclay (commercially available as Bentone MA from Rheox Inc.) was added tothe water/PTFE/quat mixture for about 5 minutes. The resulting mixturewas transferred to a glass jar and the material floating at the top(“coagulate”) was collected and dried in an oven at 50° C. for 24 hours.After drying, the coagulate composition was ground with a spatula on aglass plate to a powdery consistency.

2.3 grams of the PTFE/organoclay composition was added to 50 grams oftoluene in a glass beaker and mixed in a Hamilton Beach model 936-2(commercially available from Hamilton Beach, Inc. located in Washington,N.C.) at a Variac setting of 40 for about a minute on a magneticstirrer. This step was repeated in separate glass beakers, whichrespectively contained 50 grams of Sunpar LW 120 oil (produced by ExxonCorp.) and 50 grams of Magiesol 47 (produced by Magie Bros. Oil Co.). Asa control, 2.3 grams of the same PTFE was added and mixed in the sameamount of each solvent above. When these test mixtures were checkedunder the microscope, the PTFE/organoclay was well dispersed in thetoluene, i.e., showed virtually no aggregates. However, the other twoPTFE/organoclay test samples showed some aggregates. The pure PTFE testsamples showed a significant number of aggregates.

0.25 grams of acetone was added to each test sample having aggregates,i.e., all test samples except for the PTFE/organoclay test sample intoluene. After adding the acetone, each test sample was mixed in theHamilton Beach for about one minute. When these test mixtures werechecked under the microscope, the PTFE was well dispersed in all of thePTFE/organoclay test samples. However, all of the pure PTFE test samplesstill showed a significant amount of aggregates. The results aresummarized in Table 1 below: TABLE 1 Dispersion of PTFE andPTFE/Organoclay in Organic Solvents Invention PTFE/Organoclay Aggregatesof Examples Powder (grams) Organic Solvent Acetone (grams) PTFE 1 2.5 50grams of toluene — none 2 2.5 50 grams of Sunpar 0.25 none LW 120 3 2.550 grams of 0.25 none Magiesol 74 Comparative Pure PTFE Aggregates ofExamples (grams) Organic Solvent Acetone (grams) PTFE A 2.5 50 grams oftoluene 0.25 yes B 2.5 50 grams of Sunpar 0.25 yes LW 120 C 2.5 50 gramsof 0.25 yes Magiesol 74

The results of this experiment show that the PTFE/organoclay compositionsignificantly increases the dispersion of PTFE in organic solvents ascompared with the dispersion of PTFE alone.

Example 2 Dispersion of PTFE and PTFE/Organoclay in PolyethylenePreparation of Bentonite Clay Slurry

Solid bentonite clay was dispersed by slowly mixing about 3% by weightof bentonite in 97% by weight of water at room temperature. This mixturewas mixed for 8 hours in a high-speed mixer to obtain a clay slurry.Without wanting to be limited to any one theory, it is believed thatthis mixing step helps to separate out the individual platelets of thebentonite clay. After allowing the clay mixture to stand for 24 hours atroom temperature, the clay slurry was separated from the waste thatsettled to the bottom by decanting. A small portion of the clay slurrywas then weighed and placed in an oven for 2 hours at 100° C. toevaporate out all of the water. The dried clay was then weighed todetermine the solid weight percentage of the clay in the slurry. Thesolid weight percentage of the clay was about 1.57% by weight of theclay slurry.

Preparation of Organoclay

Organoclay powder was then obtained as follows. A portion of thebentonite clay slurry was weighed, heated to 55° C., and mixed in ablender at high speed. Using the solid weight percentage of the clayobtained from the procedure above (e.g., 1.57%), a quat to clay solidweight ratio of 0.6:1.0 was selected, and the appropriate amount of quatwas added to the clay slurry. After mixing for an additional 5 minutes,the mixture was allowed to stand for about 30 minutes. Thereafter, thecoagulate floating at the top was collected, filtered, and washed withwater. The resulting solid was dried in an oven at 55° C. for 24 hours.The resulting dried solids were ground in a mortar and pestle to obtaina fine powder of organoclay.

Preparation of PTFE/Organoclay Powder Samples

A portion of the clay slurry was placed in a beaker and weighed. Theclay slurry was heated to 55° C. while mixing with a magnetic stirrerbar. The heated clay slurry was divided into three equal portions andtransferred into three blenders. PTFE (commercially available as SST 3Dfrom Shamrock Technologies, Inc.) was then slowly added while mixing athigh speed to each blender according to the proportions provided inTable 2 and using the solid weight percentage of the clay obtained fromthe previous step. TABLE 2 Formulation of PTFE/Organoclay Powder SampleBentonite PTFE PTFE/Organoclay Clay SST 3D Powder (wt. %)* Quat (wt. %)*(wt. %)* I 15.62 9.38 75 II 31.25 18.75 50 III 46.47 28.13 25*% of total weight of physical entrapment phase and characteristic useparticles

After mixing for five additional minutes, quat was added to each blenderaccording to the weight percentages provided in Table 2 above. Aftermixing for an additional 5 minutes, the mixture was allowed to stand forabout 30 minutes. Thereafter, the coagulate floating at the top of eachblender was collected, filtered, and washed with water. The resultingcomposite compositions (i.e., Samples I-III) were dried in an oven at55° C. for 24 hours. The resulting dry composite compositions wereground in a mortar and pestle to obtain a fine powder mixture oforganoclay and PTFE.

Preparation of PTFE Dispersions in Polyethylene

PTFE dispersions in powdered polyethylene (PE S394-N1 commerciallyavailable from Shamrock Technologies) were prepared by adding therespective components, as provided in Table 3 below, in a glass bottleand mixing the dry components by shaking for about 3 minutes. Theresulting dry powder mixtures were placed in a metal panel, which wasplaced on a hot plate. The panel was heated enough to melt thepolyethylene, and a spatula was used to mix the molten polyethyleneusing a backward and forward motion for 15 times (one time constitutedone backward and one forward motion). A drop of the hot polyethylenemixture was placed on a hot glass slide. A glass cover was placed on topof the glass slide to make a thin film, and the thin film was inspectedunder the microscope. The resulting observations are provided in Table3. TABLE 3 Formulation of PTFE Dispersions in Polyethylene OrganoclayPTFE Observation Under Microscope (grams) (grams) PE (grams) (125 ×Magnification) Control Samples Control PE — — 100.00 Clear, crystal andhomogeneous. See FIG. 3A Control PE + PTFE — 5.00  95.00 AgglomeratedPTFE particles Control PE + Organoclay 5.00 —  95.00 Homogeneous andclear. See FIG. 3B Invention Examples 4^(a) 1.25 3.75  95.00Concentrated and dispersed PTFE particles. See FIG. 4A Control Samples5^(b) 2.50 2.50  95.00 Dispersed PTFE particles more homogeneous. SeeFIG. 5A 6^(c) 3.75 1.25  95.00 Dispersed PTFE particles. See FIG. 6AComparative Examples D — 3.75  95.00 Agglomerated PTFE particles. SeeFIG. 4B. E — 2.50  95.00 Agglomerated PTFE particles. See FIG. 5B. F —1.25  95.00 Agglomerated PTFE particles. See FIG. 6B.^(a)5 grams of PTFE/Organoclay Sample I from Table 2 was used.^(b)5 grams of PTFE/Organoclay Sample II from Table 2 was used.^(c)5 grams of PTFE/Organoclay Sample III from Table 2 was used.

These results show that organoclay significantly improves the dispersionof PTFE in polyethylene.

Example 3 Dispersion of PTFE and PTFE/Organoclay in Mineral OilPreparation of Clay Slurry

The clay slurry was prepared as described in Example 2. However, samplesof this clay slurry were centrifuged for various time periods (from 1minute to 9 minutes) to determine the time needed to remove most of thelarge, undissolved foreign particles, as observed under a microscope.The optimum time was determined to be about 5 minutes, and the entireclay sample was centrifuged for about 5 minutes. The solid weightpercent of the bentonite clay slurry was then determined as described inExample 2.

Preparation of Organoclay/PTFE

In order to determine the appropriate amount of quat needed to reactwith the clay, five organoclay/PTFE powder mixtures were obtainedaccording to the different mass proportions provided below in Table 4.TABLE 4 Formulation of PTFE/Organoclay Powder Sample Weight PTFE/ ClayClay Ratio Organoclay Slurry (solid Clay Quat PTFE¹ of Quat/ Powder(grams) wt. %) (grams) (grams) (grams) Clay IV 200 1.66 3.32 1.992 5.3120.6 V 200 1.66 3.32 2.656 5.976 0.8 VI 200 1.68 3.36 1.328 4.648 0.4 VII200 1.68 3.36 2.352 5.712 0.7 VIII 200 1.68 3.36 2.352 0.00 0.7¹PTFE SST-3D (commercially available from Shamrock Technologies, Inc.)

In each of the above five samples, the clay slurry was placed in a 250mL beaker and heated on a hot plate to 65° C. The heated clay slurry wastransferred into a 1 liter blender. The PTFE was slowly added and mixedfor about 3 minutes with the blender set at speed 1. While the PTFE wasbeing mixed, the quat was dissolved in 120 grams of water at atemperature of 65° C. The quat solution was then poured into the blenderand mixed with the PTFE and clay for about 10 minutes with the blenderset at speed 1.

Each organoclay/PTFE mixture was then poured into a jar and allowed tostand for about ½ hour. The organoclay/PTFE agglomerated at the top ofliquid mixture and eventually provided a two phase system: the bottomphase was clear water; the top phase was the organoclay/PTFE. Theaqueous phase containing the clay slurry has been a brownish-clay colorbefore the quat was added. The top phase agglomerate was separated,filtered, and rinsed with water. Then the composite composition wasdried in an oven at 50° C. for 24 hours. Finally the dry compositecomposition was ground with a spatula on a lab bench for approximately10 minutes. TABLE 5 Visual Observations of Samples at Various Quat/ClayRatios Weight Ratio Sample ID of Quat/Clay Observations Before FilteringObservations of Dry Solid IV 0.6 Sample IV had two phases. Most of theSample IV was a soft solid that solids (PTFE, Quat and clay)agglomerated was easy to grind into a powder. at the top of the samples.The water phase was clear V 0.8 Similar to Sample IV. Sample V had avery Sample V was the softest solid, clear water phase. which was veryeasy to grind into a powder. VI 0.4 Sample VI had a single uniform phasewith Sample VI was very hard and a beige color. very difficult to grind.VII 0.7 Sample VII had two phases. Most of the Sample VII was thesoftest solid, solids (PTFE, Quat and clay) agglomerated which was veryeasy to grind into at the top of the samples. The water phase a powder.was as clear as Sample IV. VIII 0.7 Sample VIII had two phases. Most ofthe Sample VIII was a soft solid. solids (quat and clay) agglomerated atthe top of the samples. The water phase was as clear as Sample IV.

According to the observations provided in Table 5 above, a Quat to clayweight ratio range from about 0.6 to about 1 was found to be effectivein converting the clay into organoclay. A Quat to clay weight ratiorange from about 0.7 to about 1 was preferred, and a ratio range fromabout 0.8 to about 1 was more preferred.

Preparation of PTFE Dispersions in Mineral Oil

Mineral oil and acetone were added to six plastic containers accordingto the proportions provided in Table 6 below. While stirring with amagnetic stirrer, the dried solids were added to the mineral oil/acetonemixture. TABLE 6 Formulation of PTFE Dispersions in Mineral Oil OC/PTFE¹OC/PTFE² Mineral Organoclay 1:1 wt. 1:1 wt. Oil Acetone 0.7/1 Quat/clayPTFE ratio ratio (grams) (grams) (grams) (grams) (grams) (grams) ControlSamples Mineral 100 0.200 — — — — Oil/Acetone Mineral 100 0.200 1.0 — —— Oil/Acetone/Organoclay Invention Examples 7 100 0.200 — — 2.0 — 8 2500.625 — — — 5.0 Comparative Examples G 100 0.200 — 1.0 — — H 250 0.625 —2.5 — —¹Organoclay having Quat/Clay ratio of 0.7/1 from Sample VII in Table 4was used.²Organoclay having Quat/Clay ratio of 0.8/1 from Sample V in Table 4 wasused.

The samples were then mixed for a period of about 3 minutes with thestirrer speed setting at 4 on the magnetic plate. The samples wereobserved under the microscope and the observations were recorded.Thereafter, the samples were then mixed in a Waring blender for a periodof about 10 minutes at a speed setting of 1, and were again observedvisually and at a magnification of 125×.

Finally, the Control Samples, Invention Example 7 and ComparativeExample G were sonicated for a period of about 5 minutes at fullintensity in a model UC 100 Sonicator (Vibray Cell), (commerciallyavailable from Sonics Materials Company located in Danbury, Conn.).These samples were again observed visually and at a magnification of125×. Invention Example 8 and Comparative Example H were separatelymixed and ground using the horizontal mill (4 passes at a RPM of 2600with 0.8-1.0 mm ceramic beads), which is commercially available as MiniMotormill 100 from Eiger Machinery Inc. These samples were againobserved visually and at a magnification of 125×, and the results areshown in Table 7 below: TABLE 7 Visual and Microscopic Observations ofMineral Oil Dispersions Microscopic Observations Visual Observations (at125 × magnification) Control Samples Mineral The sample was clear andcolorless. No particles were present. Oil/Acetone Mineral The organoclaydispersed well in mineral oil. Small and medium sized crystallineparticles Oil/Acetone/Organoclay However, some light brown solidssettled to were observed. the bottom of the contain after about 5minutes. This observation was unchanged even after this solution wasmixed using a magnetic stirrer bar, blender and sonicator. InventionExamples 7 Same observations as Mineral The particles were agglomerated.Oil/Acetone/Organoclay Control Sample, except the color was lighter. 8The particles were well dispersed. After The particles are welldispersed. See FIG. 7A about 2 hours, some of the particles started tosettle. The color of this sample was tan. Comparative Examples G ThePTFE did not disperse even after mixing Agglomerated particles wereobserved. These with a spatula. The agglomeration of the particles werelarger than those observed in PTFE was easily observed. The overall theMineral Oil/Acetone/Organoclay Control sample was cloudy. Sample. H Sameobservations as Comparative Example Agglomerated particles wereobserved. See G, except that this sample was foamy. FIG. 7B.

The visual observations of the solutions and the microscopic pictures,shown in FIGS. 7A and 7B, of the samples of Invention Example 8 andComparative Example H showed that organoclay (OC) helps to disperse PTFEin mineral oil.

Example 4 Dispersion of Polyethylene in Isopropyl Alcohol

Preparation of Clay Slurry

A clay slurry using bentonite clay was prepared according to Example 3.

Preparation of Organoclay/PE and Organoclay/PTFE

Two samples were prepared according to a ratio of 0.75 grams of quat to1 gram of clay. The clay slurry above was found to have 1.57% by weightof clay. Bentonite clay contains 3% by weight of Na and quat contains 7%by weight of Cl. The proportions for the samples are provided in theTable 8 below: TABLE 8 Formulation of Organoclay/PE and Organoclay/PTFEWt. Ratio Clay Clay Sample (Quat/ Slurry (wt Clay Quat PE² WVP¹ ID Clay)(gram) %) (gram) (gram) (gram) (gram) IX 0.75 350 1.57 5.506 4.130 9.1820.000 X 0.75 350 1.57 5.506 4.130 0.000 9.182¹WVP means Daikin F104 white virgin PTFE particles, Shamrock Technologydesignation Powdertex 53²PE was S-395N1, which is commercially available from ShamrockTechnology and which has an average diameter of 5 microns.

The clay slurry was placed in a 500 mL beaker and heated on a hot plateat a temperature of about 70° C. The heated clay slurry was transferredinto a 1 liter blender. The blender was set at a mixing speed of 1, andPE powder was slowly added and mixed for about 3 minutes. While PE wasbeing mixed in the clay solution, quat was dissolved in 150 grams of hotwater at a temperature of about 65° C. This quat solution was thenpoured into the blender and mixed with the PE and clay for about 10minutes. The organoclay/PE mixture (“OC/PE mixture”) was then pouredinto a jar to observe how the OC/PE agglomerated to the top of the jar.After allowing the sample to stand for about 30 minutes, the OC/PEmixture was filtered and the solids of each sample were dried in an ovenat 50° C. for about 24 hours. This procedure was repeated for the OC/WVPsample (white virgin PTFE).

Dispersions of these samples in isopropyl alcohol were then preparedaccording to the proportions provided in Table 9 below: TABLE 9Formulation of PE Dispersions in IPA OC/PE (wt % ratio˜1:1)^(a) SampleID IPA (grams) PE (grams) (grams) Invention 10 0.00  0.20^(b) Example 8Comparative 10 0.20 0.00 Example I^(a)Organoclay weight ratio of 0.75/1 for Quat/Clay^(b)Sample IX from Table 8 was used.

The dried solids (OC/PE) were ground with a spatula on a glass plate forapproximately 10 minutes. 0.2 grams of PE and OC/PE were then separatelyplaced in two 15 mL test tubes. Then 10 mL of isopropyl alcohol (IPA)was added to each test tube. Both samples were shaken by hand for aperiod of 10 seconds and pictures were taken at a magnification of 125×,as illustrated by FIGS. 8A and 8B. The visual and microscopicobservations are provided in the Table 10 below: TABLE 10 Visual andMicroscopic Observations of IPA Samples Sample ID Visual ObservationMicroscopic Observation Invention After shaking the test tube Themicroscopic pictures Example 8 for 10 seconds, it was show that observedthat the OC/PE OC/PE is well immediately dispersed in the dispersedwithout any IPA providing a tan color. agglomeration See FIG. When thetest tube was 8A. decanted, no OC/PE was left at the bottom of the testtube. Comparative After shaking this test The microscopic pictureExample I tube containing IPA and PE, it shows was observed that theagglomeration of the PE did not disperse completely. PE particles. SeeIts color was cloudy, and FIG. 8B. large particles settled down to thebottom of the test tube.

The visual and microscopic observations reported in Table 10 ofInvention Example 8 and Comparative Example I show that OC/PE disperseswell in IPA without any agglomeration, as illustrated by FIG. 8A. Incontrast, as shown in FIG. 8B, PE does not disperse well in IPA, asevidenced by the large amounts of agglomerates of PE.

Samples of the OC/WVP, which were obtained above, and WVP without OCwere also analyzed by conducting a rubbing test. The procedure is asfollows: approximately 0.5 grams of WVP and OC/WVP were separatelyplaced next to each other on a rubber mouse pad, and an index finger wasused to spread out the dry powders on the mouse pad. The OC/WVP spreadout very easily, while the WVP particles adhered to each other to formlarger balls or aggregates of particles.

Example 5 Grind Gauge and Settling Tests for Dispersions of PTFE inMineral Oil Preparation of Clay Slurry

A clay slurry using bentonite clay was prepared according to Example 3.

Preparation of Organoclay/PTFE Powder

According to a previous experiment in Example 3, it was found that about0.6 grams of quat is required for 1 gram of clay to effectively convertthe bentonite clay into organoclay. Using the 0.6:1 ratio, seven sampleshaving varying organoclay to PTFE ratios were prepared according theproportions provided in Table 11 below, wherein SST-3D PTFE was used.TABLE 11 Formulation of OC/PTFE Powder Clay Clay PTFE OC Slurry (solidClay Quat OC* PTFE OC + PTFE (% by (% by Sample (g.) wt. %) (g.) (g.)(g.) (g.) (g.) wt.) wt.) XI 0.00 1.12 0.00 0.00 0.00 20.00 20.00 100.000.00 XII 10.00 1.12 0.11 0.07 0.18 17.74 17.92 99.00 1.00 XIII 20.001.12 0.22 0.13 0.36 13.98 14.34 97.50 2.50 XIV 50.00 1.12 0.56 0.34 0.9017.02 17.92 95.00 5.00 XV 100.00 1.12 1.12 0.67 1.79 16.13 17.92 90.0010.00 XVI 200.00 1.12 2.24 1.34 3.58 8.36 11.95 70.00 30.00 XVII 200.001.12 2.24 1.34 3.58 3.58 7.17 50.00 50.00*No correction was made for weight loss of by product NaCl whenorganoclay is formed

Using the proportions in the above table, Samples XI-XVII wereseparately prepared as follows. The clay slurry was placed in a 250 mLbeaker, enough water was added to reach the 200 mL mark, and the samplewas then heated to 65° C. After transferring the heated clay slurry to a1 liter blender, PTFE was slowly added to the mixture in the blenderwhile mixing at a blender speed setting of 1. While the PTFE/claymixture was being mixed for about 3 minutes, the appropriate quantity ofquat according to the proportions in the above table, was dissolved in120 grams of hot water at 65° C. The quat solution was then added to themixture in the blender and mixed for about 10 minutes at a blender speedsetting of 1. The resulting organoclay/PTFE mixture (“OC/PTFE”) was thenpoured into a jar and allowed to sit for about 30 minutes. The OC/PTFE,which agglomerated at the top of the jar, was separated by filtration,and the solids were dried in an oven for about 24 hours at 65° C. Thedried sample was then ground for about 2 minutes in a Bel Art grindingmachine.

Preparation of PTFE Dispersions in Mineral Oil

Seven PTFE dispersions in mineral oil, using the OC/PTFE powdersobtained in the previous step were prepared according to the proportionsprovided in Table 12 below: TABLE 12 Formulations of PTFE in Mineral OilPTFE Mineral Oil Acetone OC/PTFE* Samples (wt %) OC (wt %) (grams)(grams) (grams) 10 100.0 0.0 160.0 0.8 3.200^(a) 11 99.0 1.0 160.0 0.83.232^(b) 12 97.5 2.5 160.0 0.8 3.282^(c) 13 95.0 5.0 160.0 0.83.368^(d) 14 90.0 10.0 160.0 0.8 3.555^(e) 15 70.0 30.0 160.0 0.84.572^(f) 16 50.0 50.0 160.0 0.8 6.400^(g)*PTFE concentration was fixed at 3.2 g PTFE to 160 g mineral oil.^(a)Sample XI from Table 11 was used.^(b)Sample XII from Table 11 was used.^(c)Sample XIII from Table 11 was used.^(d)Sample XIV from Table 11 was used.^(e)Sample XV from Table 11 was used.^(f)Sample XVI from Table 11 was used.^(g)Sample XVII from Table 11 was used.

Containers were first filled with mineral oil and acetone according tothe proportions in the above table. The mineral oil/acetone mixtureswere then placed in a 1 liter blender and mixed for a few seconds at aspeed setting of 2 while the OC/PTFE was added. The total mixture wasthen mixed for a period of about 2 minutes at the blender speed settingof 7. The samples were then placed in 75 mL test tubes to study thesettling rate as a function of organoclay concentration, as describedbelow. A grind gauge test was also performed to check agglomeration andparticle size, as described below.

Settling Test for Mineral Oil Dispersions

The seven 75 mL test tubes prepared above were filled to a top lineheight of 7.03 inches from the bottom of the test tubes. Threeadditional lines were drawn on each of the test tubes: (i) a first lineat about 6.25 inches below the top line height; (ii) a second line atabout 5.69 inches below the top line; and (iii) a third line at 3.34inches from the top line, as illustrated in FIG. 9. The time needed forphase separation, i.e., settling, was observed and recorded by trackingthe progress of the top of the white phase from the top line. As the topof the white phase decreased in height, the amount of a clear mineraloil phase increased on top of the white phase. The settling time resultsare summarized in Table 13 below. TABLE 13 Settling Time Results ratioof settling PTFE OC* Line Line Line length/time rate to Sample (wt %)(wt %) 1(hrs) 2(hrs) 3(hrs) to line 1(hr) sample 10 Comments 10 100.000.0 0.3472 n/a n/a 18.0029 1.00 Under line 1 11 99.0 1.0 0.4138 n/a n/a15.1027 1.19 Under line 1 12 97.5 2.5 0.4417 n/a n/a 14.1509 1.27 Underline 1 13 95.0 5.0 0.5875 n/a n/a 10.6383 1.69 Under line 1 14 90.0 10.02.688 0.69 n/a 2.3244 7.75 Under line 1 15 70.0 30.0 — 5.78 46.67<0.0166 1083.17 After 361 hours, the top of the white phase was 6 inchesbelow the top line 16 50.0 50.0 — — — <<0.0125 1444.23 After 361 hours,the top of the white phase was 4.5 inches below the top line*No correction was made for weight loss of byproduct NaCl

The first and second columns represent the mass % of PTFE andorganoclay, respectively, for each sample. The fourth, fifth and sixthcolumns show the time required for the PTFE and organoclay to settle upto lines 1, 2, and 3, respectively. These results show that as theconcentration of organoclay increases the settling rate decreases. Inother words, adding more OC to each sample will result in a longersettling time for the PTFE. In fact, the OC/PTFE in Samples 15 and 16did not even settle to line I even after 361 hours (roughly 2 weeks).Graphical illustrations of these results are provided in FIGS. 10A and10B, which plot the ratio (of the settling rate to Sample 10) versus theorganoclay weight percent. Furthermore, the OC/PTFE material of Samples11-14 “soft settled,” meaning that the settled material is readilyre-dispersed with gentle mixing of the test tube by hand. In contrast,the material of Sample 10 “hard settled,” meaning that the settledmaterial was difficult to redisperse, even after vigorous shaking of thetest tube by hand.

Grind Gauge Observations for the Mineral Oil Dispersions

Each sample in Table 13 was shaken by hand right before the grind gaugetest was performed. Using a 5-mL plastic pipette, about 2 mL of eachsample was placed on top of the grind gauge. The draw down wasperformed, and the observations were recorded. These observationscorrespond to samples 10 to 16 from Table 12. TABLE 14 Observations ofMineral Oil Dispersion under the Grind Gauge Sample PTFE OC ID (wt %)(wt %) Observations 10 100.0 0.0 Large quantity of large particles. Theparticles size were within the range of 0-80 μm on Hegman with manylarge particles at 80 μm. Hegman grind gauge values of 0-100 μ 1½-80 μ11 99.0 1.0 Almost clean a few particles at 22 μm. Very few scattered.Particles on Hegman up to 60 μm. 12 97.5 2.5 This sample is much betterthan the previous sample, only a few particles seen. 13 95.0 5.0 Clean,no particles observed for both grind gauges (NPRI + Hegman)¹ 14 90.010.0 Same as sample 13 15 70.0 30.0 Same as sample 13 16 50.0 50.0 Sameas sample 13¹NPRI is another type of grind gate, wherein a value of 10 means ˜25 μm;8 means ˜20 μm, 6 means ˜15 μm, 4 means ˜10 μm, 2 means ˜5 μm, and 0means˜μm.

The results in Table 14 above show that organoclay can help PTFEdispersion in mineral oil even at a low OC weight percent of 1.0. As theconcentration of organoclay increases, the particle size decreases, aswell as the number of large particle size aggregates (scatter).

Example 6 Dispersion of TiO₂ in Mineral Oil

Preparation of Clay Slurry

The clay slurry was prepared as described in Example 2, however a 36×20Mark III Centrifuge (commercially available from ATM/Delaval Co.) wasused after mixing the bentonite clay in water for about 5½ hours. Thecentrifuge was operated at about 1625 RPM and an air pressure setting of7 psi, which was previously determined to be the equivalent of 8.85 GPM.It took about 5¾ hours for all of the clear clay slurry to overflow thebowl centrifuge.

The solid weight percent of the bentonite clay was then determined asdescribed in Example 2, however these samples were tested: a 5 gramsample, a 10 gram sample, and a 15 gram sample. The solid clay weightpercentage was averaged for the three samples, and was determined to be2.120%.

Preparation of Organoclay/TiO₂

According to previous experiments, it was found that the optimum weightratio was about 0.7 to 0.8 gram of quat for every gram of clay. A 0.8 gquat to 1 g clay ratio was selected to ensure that adequate quat waspresent. Using that quat/clay ratio, eight organoclay/TiO₂ samples wereprepared according to the proportions provided in Table 15 below: TABLE15 Formulation of OC/TiO₂ Clay Slurry Clay Quat OC* TiO² OC/TiO₂ Sample# TiO₂ % OC % (gram) (gram) (gram) (gram) (gram) (gram) XVIII 0 100 50010.6 8.48 19.08 0 19.08 XIX 20 80 222.22 4.711 3.769 8.48 2.12 10.6 XX40 60 156.67 3.533 2.827 6.36 4.24 10.6 XXI 60 40 111.11 2.356 1.98444.24 6.36 10.6 XXII 80 20 55.56 2.12 0.942 2.12 8.48 10.6 XXIII 90 1027.78 0.589 0.471 1.06 9.54 10.6 XXIV 95 5 13.89 0.294 0.236 0.53 10.0710.6 XXV 100 0 0 0 0 0 10.6 10.6*Not corrected for NaCl by-product

Using the proportions in Table 15 above, Samples XVIII-XXIX were eachprepared separately as follows. The clay slurry was placed in a 700 mLbeaker and then heated to 60° C. After transferring the heated clayslurry to a Waring blender, titanium dioxide was slowly added to theclay slurry while mixing at a blender speed setting of 6. The titaniumdioxide is commercially available in KR 2078 from Kronos, Inc., locatedin Hightstown, N.J. While the TiO₂/clay mixture was being mixed forabout 3 minutes, the appropriate amount of quat, according to theproportions in the above table, was dissolved in 100 grams of hot waterat 65° C. The quat solution was then added to the mixture in the blenderand mixed for about 5 minutes at a blender speed setting of 4. Theresulting organoclay/TiO₂ mixture (“OC/TiO₂”) was then poured into a jarand allowed to sit for about 30 minutes. The OC/TiO₂, which agglomeratedat the top of the jar, was separated by filtration, and the recoveredagglomerate was dried in an oven for about 24 hours at 55° C. The driedsample was then ground for about 2 minutes in a Bel Art grindingmachine.

Preparation of TiO₂ in Mineral Oil

Five TiO₂ dispersions in mineral oil, using the TiO₂/PTFE powdersobtained in the previous step were prepared according to the proportionsprovided in Table 16 below. TABLE 16 Formulations of TiO₂ in Mineral OilMineral Acetone OC/TiO₂ Sample ID TiO₂ (wt. %) OC (wt. %) Oil(gram)(gram) (gram) 17 100 0 150 0.5 1.5^(a) 18 100 0 150 0 1.5^(b) 19 95 5150 0.5 1.5^(c) 20 90 10 150 0.5 1.5^(d) 21 60 40 150 0.5 1.5^(e)^(a)Sample XXV from Table 15 was used.^(b)Sample XXV from Table 15 was used.^(c)Sample XXIV from Table 15 was used.^(d)Sample XXIII from Table 15 was used.^(e)Sample XXI from Table 15 was used.

Five containers were first filled with mineral oil and acetone accordingto the proportions in Table 16 above. The mineral oil/acetone mixtureswere then placed in a Waring blender and mixed for about 1 minute at ablender setting of 2 while the OC/TiO₂ was added. The total mixture wasthen mixed for a period of about 2 minutes at a blender speed setting of6. The samples were then placed in separate containers to study thesettling rate as a function of organoclay concentration and to performthe Hegman grind gauge test to check agglomeration and particle size.The results and observations are provided in Table 17 below. Pictureswere also take at 125× magnification. TABLE 17 Results and Observationsof TiO₂ Dispersions in Mineral Oil Sample Microscopic ID VisualObservation Observation Grind gauge Results 17 Virtually all of A lot ofMany large particles the TiO₂ particles agglomeration were present.completely settled to could be The Hegman the bottom of the detected.See gauge container after a FIG. 11A. reading was few seconds. 0(i.e., >100 micron). 18 The sample A lot of Same as above remaineddispersed for agglomeration but the particle about 5 minutes, could besizes were less then settled (around detected. than the above. 95% ofthe See sample was settled). FIG. 11B. 19 The sample A few The Hegmangauge remained dispersed for specks of reading was about ½ hour,agglomeration 5 (i.e., about after which part of the could be 40 micron)with a sample settled detected. very few particles (e.g., about 40% SeeFIG. 11C. up to 80 settled). micron 20 The sample A few The Hegman gaugeremained dispersed for specks of reading was about ½ hour, agglomeration5.5 (i.e., about after which part of the could be 35 micron) with asample settled detected. few particles of (e.g., about 40% See FIG. 11D.up to 80 micron. settled). 21 The sample No The Hegman gauge remaineddispersed for agglomeration reading was about ½ hour, could be 17.5(i.e., about after which part of the detected. 4 micron) with samplesettled See 2 particles up (e.g., about 20% FIG. 11E. to 40 micron.settled).

The results in Table 17 show that organoclay can help TiO₂ dispersion inmineral oil even at a low OC concentration of 5.0% by weight andsignificant increases TiO₂ dispersion at an OC concentration of 40.0% byweight. In fact, as the concentration of OC was increased from 0 to 40%by weight, a corresponding improvement of the Hegman grind gauge readingwas observed from 0 to 5.5.

Example 7 Determining Size Profiles of the Clusters and Agglomerates ofthe Characteristic Use Particles

The following four samples were tested using the above-describedautomatic sieve test for three minutes under vacuum at approximately 14inches of H₂O: (i) a S395 N1 polyethylene sample, (ii) anorganoclay/S395 N1 polyethylene sample, (iii) a Powdertex 53 PTFEsample, (iv) and an organoclay/Powdertex 53 PTFE sample. Theorganoclay/S395 N1 polyethylene sample and the organoclay/Powdertex 53PTFE sample were respectively prepared according to Example 4 describedabove, except that the samples were ground in a Waring blender for about30 seconds at a speed setting of 7. The results of the screening testare provided below in Table 18. TABLE 18 Screen Test Results forPolyethylene and PTFE S395 N1 Polyethylene ¹(wt. % Organoclay/S395 N1 ofsample collected Polyethylene ¹(wt. % of under screen) sample collectedunder screen) 1 Min, 26.0% 97.6% 2 Min, 33.0% 99.2% 3 Min 40.0% 99.6%Powdertex 53 PTFE ²(wt. % Organoclay/Powdertex of sample collected 53PTFE ²(wt. % of under screen) sample collected under screen) 1 Min,28.0% 92.3% 2 Min, 34.0% 95.6% 3 Min 41.0% 96.6%¹A #230 mesh size screen was used.²A #50 mesh size screen was used.

As provided in Table 18 above, both organoclay/Polyethylene andorganoclay/PTFE reflect a dramatic improvement in screening rate (e.g.,wt. % collected underneath the screen per total time of screening) incomparison to pure PE and PTFE as indicated in the first minute. Withoutwanting to be limited by any one theory, it is believed that this datareflects the decreased size and occurrence of clusters and/oragglomerates of the PTFE and polyethylene particles resulting from theaddition of organoclay.

The same four samples were tested in the Malvern particle size analyzer,as described above. The results are provided below in Table 19: TABLE 19Malvern Particle Size Results for Polyethylene and PTFE Sample VolumeWeighted Mean (μm) S395 N1 Polyethylene 10.776 Organoclay/S395 N1 PE7.235 Powdertex 53 PTFE 189.277 Organoclay/Powdertex 53 PTFE 86.043

As provided in Table 19, the Malvern analysis provides a significantdecrease in the volume weighted mean size of the clusters and/oragglomerates of the samples having organoclay compared to the puresamples of Powdertex 53 PTFE and S395 N1 polyethylene. These results arein accordance with the screen test results provided in Table 18.

Example 8 Dispersion of Hydrous Oxide/PTFE in Water

About 5 grams of TiOSO₄ are dissolved in about 100 mL of aqueous, 1NH₂SO₄ at 25° C. in a small beaker. Concurrently, about 3.42 grams ofSST-4 type PTFE (commercially available from Shamrock Technologies) isadded to 250 mL of hot water at about 90° C. in another beaker. Whilestirring rapidly, the solution of TiOSO₄ and H₂SO₄ is slowly added tothe 250 mL of hot PTFE/water mixture over a period of about 60 seconds.Two minutes after the addition is completed, the mixture is filtered torecover the precipitated hydrous titanium dioxide having the entrappedPTFE (“the composite”). This composite is about a 50/50 mixture of PTFEphysically entrapped in the hydrous oxide, because hydrous oxides cancontain a variable amount of water.

Before drying, the composite can then be further processed to improvedispersion in the target media. For example, the composite can bepeptized before adding the composite to a hydrophillic target medium.This can be done by rapidly stirring into the composite obtained aboveabout 250 mL of 0.05 N aqueous HCl, wherein the hydrous titanium dioxideis peptized by the dilute acid solution.

Example 9 Preparation of Carbon Black/Organoclay Compositions

After removing impurities from about 5 gallons of clay as provided inExample 6, 500 mL of clean clay slurry containing 2.12% by weight solidsis heated to 65° C. After transferring the heated clay slurry to aWaring blender, 53 grams of pigment grade carbon black (commerciallyavailable from Cabot Corporation) is slowly added to the clay slurrywhile mixing at a blender speed setting of 7. While the carbonblack/clay mixture. is mixed for about an additional 5 minutes, a quatsolution is separately prepared by adding 7.42 grams of dry 2M2HT quat(commercially available from Witco Corp. as Adogen 442-100P) to 125 mLwater at about 65° C. and mixing for about 5 minutes. The quat solutionis then added to the carbon black/clay mixture in the blender and mixedfor about an additional 10 minutes at a blender speed setting of 4. Theresulting organoclay/carbon black mixture (“OC/CB”) is then poured intoa jar and allowed to sit for about 30 minutes. The agglomerated OC/CB isseparated by filtration, washed with about 250 mL of water at about 65°C., and the recovered agglomerate is dried in an oven for about 24 hoursat about 60° C. The dried sample can then be ground into powder form.

Example 10 Preparation of Calcium Carbonate/Organoclay Compositions

After removing impurities from about 5 gallons of clay as provided inExample 6, 500 mL of clean clay slurry containing 2.12% by weight solidsis heated to 65° C. After transferring the heated clay slurry to aWaring blender, 126.14 grams of calcium carbonate (commerciallyavailable from Omya, Inc. as omyacarb 3) is slowly added to the clayslurry while mixing at a blender speed setting of 7. While the carbonblack/clay mixture is mixed for about an additional 5 minutes, a quatsolution is separately prepared by adding 7.42 grams of dry 2M2HT quat(commercially available from Witco Corp. as Adogen 442-100P) to 125 mLwater at about 65° C. and mixing for about 5 minutes. The quat solutionis then added to the calcium carbonate/clay mixture in the blender andmixed for about an additional 10 minutes at a blender speed setting of4. The resulting organoclay/calcium carbonate mixture (“OC/CC”) is thenpoured into a jar and allowed to sit for about 30 minutes. Theagglomerated OC/CC is separated by filtration, washed with about 250 mLof water at about 65° C., and the recovered agglomerate is dried in anoven for about 24 hours at about 60° C. The dried sample can then beground into powder form.

Example 11 Preparation of Submicron PTFE/Organoclay Compositions

Submicron PTFE in IPA was formulated as follows. White virgin paste(WVP) PTFE, irradiated by an electron beam at 28 megarads was gentlyadded to IPA at a concentration of 25% while mixing. Using a horizontalmill with 0.6 to 0.8 mm diameter beads, the mixture of irradiated PTFEand IPA was ground at a speed of 3500 RPM. To avoid settling, themixture of irradiated PTFE and IPA was constantly mixed. After 5 passesof grinding, 100% of the particles had a particle size of less than 0.5μm. It is generally expected that the dispersion will be completelysubmicron after 7 to 10 passes of grinding. Particle size analysis datafor the PTFE/IPA dispersion are shown in FIGS. 14A and 14B.

Pure submicron PTFE powder was formulated as follows. To three gallonsof hot. water (60° C.), 1600 grams of the submicron PTFE/IPA dispersionformed above was gently added and mixed for 15 minutes. The mixture wasthen allowed to sit for 30 minutes. During this time, the PTFE floatedto the top of the water/IPA mixture. The PTFE was then removed to analuminum tray and dried in an oven at approximately 60° C. The remainingwater/IPA mixture was filtered using a #1 filter paper and an air vacuumor water vacuum. Particle size analysis was performed on the puresubmicron PTFE powder product, and the particle size analysis data forthe submicron PTFE powder are shown in FIGS. 12A and 12B.

Submicron PTFE in IPA-Quat was formulated as follows. The mixture ofPTFE in IPA/Quat comprised 25% White Virgin Paste (WVP) PTFE that hadbeen irradiated at 28 megarads, 73% IPA, and 2% Quat, wherein the Quatused was 2M2HT, described in the above Examples. The Quat was firstdissolved in the IPA, and the PTFE was gently added to the IPA/Quatmixture while mixing. A horizontal mill was used to grind the PTFE inIPA/Quat mixture while constantly mixing. The particle size was checkedafter 5 passes of grinding and was found to be less than 0.5 μm. Theparticle size results for the mixture of PTFE, IPA and Quat are shown inFIGS. 15A and 15B. The procedure for filtering and drying the submicronPTFE is as described above.

Lastly, the submicron PTFE/organoclay powder composition was produced asfollows. For preparation of submicron clay in water, a 20% white clayslurry was ground in a horizontal mill. The particle size was checkedafter 15 minutes. The clay particles will normally be of submicron sizeafter about 25-30 minutes.

The amount of clay to be added to the mixture of IPA, Quat and submicronPTFE was calculated to be in a ratio of one part solid clay to 0.4 partof Quat. To three gallons of hot water (60° C.), the clay was addedslowly and mixed at high speed. Then, 1500 grams of the submicronPTFE-IPA-Quat mixture formed above was gently added while constantlymixing. The solution was mixed for 15 minutes. After mixing, thesolution was allowed to sit for 30 minutes. The wet organoclay/PTFEmixture was then filtered and washed with warm water, followed by dryingin oven at a maximum temperature of 60° C. The PTFE/organoclaycomposition was air milled.

The concentration of the final submicron PTFE/organoclay composition wasdetermined to be 21.87% organoclay and 78.13% PTFE. Particle sizeanalysis was performed on the dried PTFE/organoclay composition, whereinthe dispersant (or the target medium) for dispersing the PTFE/organoclaycomposition was IPA. The particle size results for the dispersion ofsubmicron PTFE/organoclay in IPA are shown in FIGS. 13A and 13B. Theseresults showed the mean particle size value to be 1.642 μm and showedthat 72.74% of the particles were below 1.00 μm in size. Thus, thisExample shows that submicron PTFE is suitable for use as an effectivecharacteristic use particle to be entrapped in a physical entrapmentphase, such as an organoclay, and thereby easily dispersed into varioustarget media.

Example 12 Preparation of Reactor Latex PTFE/Organoclay Compositions

In the present Example, PTFE in its reactor latex form was used as thecharacteristic use particle, while organoclay was used as the physicalentrapment phase. As described earlier, “PTFE in its reactor latex form”simply denotes a suspension, in water, of PTFE particles in theirprimary particle size, which results from the synthesis of PTFE via anemulsion polymerization process. Specifically, the reactor latex PTFEused in this Example was a product obtained from Daikin. First, theoverall percent solids concentration of the PTFE reactor latex samplewas determined. This was done using a Computrac Max 1000 MoistureAnalyzer (commercially available from Arizona Instruments). It wasdetermined that the PTFE reactor latex sample used in this Example had asolids content of 25.0%.

Next, particle size analysis was performed on a sample of the PTFE inits reactor latex form. The particle size analysis employed the MalvernMastersizer 2000 particle size analyzer and the Malvern method describedin detail above. Specifically, a sample of the reactor latex PTFE wasdispersed in IPA, and particle size results showed the mean particlesize value to be 0.201 μm, while 100.00% of the PTFE particles wereshown to be below 1.00 μm in size. A graph of the particle sizedistribution for this sample of PTFE in its reactor latex form is shownas FIG. 16. These results simply indicate to the user that the sample ofreactor latex PTFE is readily dispersible, since 100% of the particlesdispersed to submicron size, thus indicating a low level ofagglomeration.

Subsequently, bentonite clay slurry was formed as described in Example 2above. Particle size analysis of the bentonite clay slurry showed themean particle size value of the clay particles to be about 2.2 μm. Asmall sample of this bentonite clay slurry kept at room temperature wasthen added to a small sample of the reactor latex PTFE. Particle sizeanalysis of the reactor latex PTFE/clay was performed using the Malvernmethod, and the results showed the mean particle size value of theparticles in the composition to be 1.887 μm, while 10.74% of theparticles were below 1.00 μm in size. A graph of the particle sizedistribution for this sample of the reactor latex PTFE/clay is shown asFIG. 17. In this graph, a small peak is observed below 1 μm, whichrepresents the particle size peak for the PTFE particles, while thelarger peak above 1 μm represents the clay particles.

A small sample of the reactor latex PTFE was then combined with a sampleof warm dissolved Quat. Herein, the Quat used was Adogen 442, describedabove. Particle size analysis was then performed for the PTFE/Quatmixture, and a graph of the particle size distribution for thiscomposition is shown as FIG. 18. These particle size analysis resultsindicated that the mean particle size value of the PTFE/Quat mixture was20.825 μm, and 0.00% of the particles were below 1.00 μm in size. Thus,these results indicated that the reactor latex PTFE experienced someagglomeration when combined with the warm dissolved Quat.

After the above preliminary analyses were performed, the method of thepresent invention was employed to combine PTFE in its reactor latex form(as the characteristic use particle) with organoclay (acting as thephysical entrapment phase) and then determine the dispersibility of theresulting reactor latex PTFE/organoclay compositions in a target medium.The samples of organoclay were formed having varying clay/Quat ratios sothat the effects of varying the clay/Quat ratio on the resulting reactorlatex PTFE/organoclay compositions and their dispersibility could beexamined.

All of the PTFE/organoclay compositions in the remainder of this Examplewere 50/50 reactor latex PTFE/organoclay compositions. The Clay/Quatratios used included: 1:0.6, 1:0.8, 1:1, 1:1.2, and 1:1.4. The 50/50PTFE/organoclay composition having a Clay/Quat ratio of 1:0.6 wasprepared according to the following procedure: about 30 grams of PTFE inits reactor latex form were weighed. As noted above, the percent solidsin the sample of reactor latex PTFE used herein was about 25%, so the 30grams of PTFE reactor latex comprised about 7.5 grams of solid PTFEparticles. The weighed PTFE reactor latex material was placed in a 500mL glass beaker and was allowed to stir gently using a magnetic stirringbar on a Corning hot plate with no heat. To this sample of reactor latexPTFE, 166.67 grams of Bentonite L-400 clay slurry were added. The 166.67gram sample of the clay slurry comprises about 4.69 grams of solid clay.The reactor latex PTFE and the clay slurry were allowed to mix forseveral minutes with no heating.

In a separate 250 mL glass beaker, 2.81 grams of Quat, specifically,Adogen 442 Quat, was dissolved in about 50 grams of water. From the 4.69grams of solid clay mentioned above and the 2.81 grams of Quat used, theClay/Quat ratio of about 1:0.6 was determined. The mixture of Quat andwater was stirred using a stirring bar, and was heated to about 140° F.on a Corning hot plate. When the Quat was completely dissolved, it wasadded slowly to the reactor latex PTFE/clay slurry mixture, and theresulting mixture was gradually heated to about 150° F. under gentlestirring. This mixture was allowed to react for about 45 minutes, afterwhich it was removed from the hot plate and allowed to stand for 20minutes. The resulting composition was a 50/50 reactor latexPTFE/organoclay composition having a Clay/Quat ratio of 1:0.6.

Similar procedures were employed for the 50/50 PTFE/organoclaycompositions having Clay/Quat ratios of 1:0.8, 1:1, 1:1.2, and 1:1.4,wherein only the amount of Quat dissolved was changed to createcompositions having these varying Clay/Quat ratios.

The reactor latex PTFE/organoclay compositions were first analyzed todetermine each composition's filtration time. In this analysis, a smallBuchner funnel was loaded with the same filtration media present on thepilot-plant Straight Line Belt Filter. A 100-gram well-mixed sample ofeach of the reactor latex PTFE/organoclay compositions described abovewas then filtered. Each filtration was performed under full vacuumconditions for consistency, and the filtration times for each samplewere recorded in Table 20 below: TABLE 20 Filtration Data for ReactorLatex PTFE/Organoclay Compositions at Varying Clay/Quat Ratios FilterCake Cracking Time Clay/Quat Ratio Filtration Time (seconds) (seconds)1:0.6 25 35 1:0.8 45 55 1:1.0 56 113 1:1.2 58 100 1:1.4 54 110

These results show that there is a direct relationship between the easeof filtration and the amount of Quat used in the organoclay. As theamount of Quat used in the organoclay increases, the filtration timegenerally increases.

Following the filtration analysis described above, the remainder of eachof the 50/50 reactor latex PTFE/organoclay compositions having thevarying Clay/Quat ratios was filtered using a large Buchner funnel andallowed to dry in an oven at a temperature of about 50° C. The driedfilter cake from each sample was then milled, and a dry powder form ofeach of the 5 reactor latex. PTFE/organoclay compositions resulted. Theresulting dry powder products were then analyzed visually for eachsample's characteristics, and those results are shown in Table 21 below:TABLE 21 Visual Observations of Reactor Latex PTFE/Organoclay Dry PowderProducts Having Varying Clay/Quat Ratios Overall Score (1 = Best,Clay/Quat Ratio Product Characteristics 5 = Worst) 1:0.6 Easilycompacts/fibrillates 5 1:0.8 Tendency to compact/fibrillate 3 1:1.0Tendency to compact/fibrillate 4 1:1.2 Powder more free-flowing 2 1:1.4Powder more free-flowing 1

The above results show that as the amount of Quat in the organoclayincreases, the quality of the reactor latex PTFE/organoclay compositiongenerally increases and the free-flowing nature of the resulting powdermarkedly increases. Thus, by examining the results shown in Tables 20and 21 above, it is evident that an appropriate balance must be achievedwith regard to the optimal Clay/Quat ratio to use when working with PTFEin its reactor latex form as the characteristic use particle. Thisbalance is needed because although an increase in the amount of Quatused tends to increase the free-flowing characteristics of the resultingpowder, this same increase in the amount of Quat tends to makefiltration of the reactor latex PTFE/organoclay composition more timeconsuming. Thus, for example, one might select 1:0.8 as an optimalClay/Quat ratio when using PTFE in its reactor latex form as thecharacteristic use particle because the corresponding filtration timewould be considered an acceptable filtration time under typical beltfilter processing conditions used in common manufacturing processes.

After the reactor latex PTFE/organoclay compositions described abovewere visually observed for their free-flowing characteristics, thecompositions were dispersed in a target medium, specifically mineraloil. Subsequently, particle size analysis was performed to determine howwell each of the compositions dispersed in the mineral oil. The particlesize analysis was performed using the Malvern method (described indetail above) and the Malvern Mastersizer 2000 particle size analyzer.

For the reactor latex PTFE/organoclay composition having a Clay/Quatratio of 1:0.6, the mean particle size value when dispersed in mineraloil was found to be 0.467 μm, and 93.77% of the particles in the samplewere below 1.00 μm in size. A particle size distribution graph for thissample is shown as FIG. 19. Note that 2 peaks occur in FIG. 19, one atabout 0.2 μm, which signifies the particle size distribution for thePTFE particles, and one at about 0.6 μm, which signifies the particlesize distribution for the organoclay particles. The 2 peaks, or thebimodal particle size distribution of the reactor latex PTFE/organoclaycomposition, show that the organoclay truly acts as a “physical”entrapment phase (i.e., as opposed to a chemical entrapment phase),since the organoclay particles and PTFE particles disperse into themineral oil and create 2 distinct peaks or ranges of particle size.

For the reactor latex PTFE/organoclay composition having a Clay/Quatratio of 1:0.8, the mean particle size value when dispersed in mineraloil was found to be 0.452 μm, and 94.81% of the particles in the samplewere below 1.00 μm in size. A particle size distribution graph for thissample is shown as FIG. 20.

For the reactor latex PTFE/organoclay composition having a Clay/Quatratio of 1:1.0, the mean particle size value when dispersed in mineraloil was found to be 0.426 μm, and 96.00% of the particles in the samplewere below 1.00 μm in size. A particle size distribution graph for thissample is shown as FIG. 21.

For the reactor latex PTFE/organoclay composition having a Clay/Quatratio of 1:1.2, the mean particle size value when dispersed in mineraloil was found to be 0.445 μm, and 94.97% of the particles in the samplewere below 1.00 μm in size. A particle size distribution graph for thissample is shown as FIG. 22.

For the reactor latex PTFE/organoclay composition having a Clay/Quatratio of 1:1.4, the mean particle size value when dispersed in mineraloil was found to be 0.434 μm, and 95.42% of the particles in the samplewere below 1.00 μm in size. A particle size distribution graph for thissample is shown as FIG. 23. Note that FIGS. 20-23 showed the samebimodal particle size distribution described above in conjunction withFIG. 19, as evidenced by the 2 peaks present in each of FIGS. 20-23.Again, this bimodal particle size distribution shows that the method andresulting compositions of the present invention involve physicalentrapment of the characteristic use particles as opposed to chemicalbonding or entrapment. In general, the results of this Example and ofFIGS. 19-23 show that all 5 of the reactor latex PTFE/organoclaycompositions experienced excellent dispersibility in mineral oil as thetarget medium, even though the Clay/Quat ratios were varied for thecompositions.

Example 13 Dispersion of Reactor Latex PTFE/Organoclay Compositions inIPA

In the present Example, PTFE in its reactor latex form was again used asthe characteristic use particle, and organoclay was again used as thephysical entrapment phase. The purpose of this Example was to preparereactor latex PTFE/organoclay compositions at varying concentrations ofreactor latex PTFE and then examine the dispersibility of the resultingreactor latex PTFE/organoclay compositions using IPA as the targetmedium. Specifically, reactor latex PTFE/organoclay compositions havingconcentrations of 75/25 organoclay/PTFE, 50/50 organoclay/PTFE, and25/75 organoclay/PTFE were prepared. These three reactor latexPTFE/organoclay compositions were prepared as described in Example 12above, with the only variation being the concentrations oforganoclay/PTFE of 75/25, 50/50, and 25/75, respectively.

The resulting dry powder organoclay/PTFE compositions were dispersed inIPA as the target medium and underwent particle size analysis using theMalvern method described above and the Malvern Mastersizer 2000 particlesize analyzer. A particle size distribution graph for the 75/25organoclay/PTFE composition dispersed in IPA is shown as FIG. 24,wherein the mean particle size value was found to be 0.999 μm andwherein 64.96% of the particles were shown to be below 1.00 μm in size.For the 50/50 organoclay/PTFE composition dispersed in IPA, the particlesize distribution graph included as FIG. 25 showed the mean particlesize value to be 0.471 μm and showed that 92.24% of the particles werebelow 1.00 μm in size. In addition, the particle size distribution graphfor the 25/75 organoclay/PTFE composition dispersed in IPA is includedas FIG. 26, wherein the mean particle size value was found to be 0.937μm and wherein 65.40% of the particles were below 1.00 μm in size.

FIGS. 24-26 show the bimodal particle size distribution discussed above,illustrating, once again, the physical nature of the entrapment phaseserved by the organoclay particles. In addition, in each of FIGS. 24-26,the peak representing the particle size distribution for the PTFEparticles (the peak on the left side of each graph) is well below 1.00μm, showing that the goal of the present invention, successfullydispersing a characteristic use particle such as reactor latex PTFE in atarget medium such as IPA, was achieved by using organoclay as thephysical entrapment phase in these compositions.

Example 14 Preparation of Reactor Latex PTFE/Organoclay Compositions andSubsequent Irradiation of Compositions

In the present Example, PTFE in its reactor latex form was again used asthe characteristic use particle of choice, while organoclay was againused as the physical entrapment phase. The purpose of this Example wasto examine the embodiments of the present invention wherein reactorlatex PTFE/organoclay compositions formed according to the presentmethod may be irradiated, using an electron beam, and then dispersedinto various target media.

First, in this Example, a 50/50 organoclay/PTFE composition was formedaccording to the procedure described in detail in Example 12 above.

As described in Example 12 above, the resulting 50/50 organoclay/PTFEcomposition was filtered using a Buchner funnel and allowed to dry in anoven at a temperature of about 50° C. The dried filter cake was thenmilled, and a dry powder form of the 50/50 reactor latex PTFE/organoclaycomposition resulted.

A sample of this dry 50/50 PTFE/organoclay composition (without anyirradiation) was dispersed in mineral oil and underwent particle sizeanalysis. The particle size analysis performed herein employed theMalvern method described above and the Malvern Mastersizer 2000 particlesize analyzer. Specifically, for particle size analysis, the samples inthis Example were prepared by placing 2% by weight of the formed 50/50organoclay/PTFE reactor latex composition in 98% by weight mineral oil.(The mineral oil used herein was Magiesol.) In addition, IPA in theamount of 20% of the organoclay weight was added to each sample, andeach sample was then blended in a Waring blender at speed 6 for about 2minutes. The PTFE Wet SOP described in detail above was the StandardOperating Procedure used for the particle size analysis.

The particle size distribution graph for the unirradiated sample of50/50 organoclay/PTFE is included as FIG. 19, and the particle size datashowed the mean particle size value to be 0.467 μm and showed that93.77% of the particles in the sample were below 1.00 μm in size. Asdescribed earlier, the graph in FIG. 19 shows a bimodal particle sizedistribution in that 2 distinct peaks are shown, where the peak on theleft represents the particle size distribution of the PTFE particles andthe peak on the right represents the particle size distribution of theorganoclay particles.

Subsequently, samples of the dry 50/50 reactor latex PTFE/organoclaycomposition formed as described above underwent irradiation at doses of7 megarads, 14 megarads, and 28 megarads, respectively. This irradiationwas performed using electron beam irradiation. After irradiation, eachof the samples was tested for particle size by being dispersed intomineral oil according to the detailed procedure above. The particle sizeanalysis measurements were taken for each sample. For the sample ofreactor latex PTFE/organoclay irradiated at 7 megarads, the particlesize distribution graph is shown as FIG. 27, where the mean particlesize value was found to be 73.964 μm, and wherein 8.19% of the particleswere below 1.00 μm in size. The graph of FIG. 27 shows the bimodalparticle size distribution described above, wherein 2 distinct peaks areapparent for the PTFE particles and the organoclay particles.

For the sample of reactor latex PTFE/organoclay irradiated at 14megarads, the particle size distribution graph is included as FIG. 28,wherein the mean particle size value was found to be 104.657 μm, andwherein 8.76% of the particles were below 1.00 μm in size. Again, abimodal particle size distribution was observed.

For the sample of reactor latex PTFE/organoclay irradiated at 28megarads, the particle size distribution graph of is included as FIG.29, wherein the mean particle size value of the particles was found tobe 58.176 μm, and wherein 17.75% of the particles were found to be below1.00 μm in size. Similarly to the graphs described above, a bimodalparticle size distribution was observed.

By comparing the 3 particle size distribution graphs shown in FIGS.27-29, these results showed that as the intensity of the irradiation wasincreased to 28 megarads, the volume percentage of the first peak (thepeak on the left side of each graph that represents the distribution ofthe PTFE particles) greatly increased, thereby showing enhanceddispersibility of the PTFE as the level of irradiation increased.

Visual observations of the 3 samples (irradiated at 7, 14, and 28megarads, respectively) also showed that the flowability of theorganoclay/PTFE compositions increased as the dosage of irradiationincreased, while the stickiness of the samples (and therefore theability of the samples to clump or agglomerate) decreased significantlywith increasing irradiation dosage.

Further qualitative observations were performed to determine the effectsof the irradiation on the PTFE/organoclay products. In theseobservations, a small amount (about 1 gram) of each of the samples wasindividually placed in the palm of the user's hand. Using a finger fromthe opposite hand, the user spread the powder around using a circularmotion, while gently pressing down as the organoclay/PTFE powdercomposition moves between the palm and the finger. The shearing forceproduced between the palm and the finger caused the unirradiated sampleof the 50/50 organoclay/PTFE powder composition to fibrillate, ball upand exhibit stickiness. However, the samples of the 50/50organoclay/PTFE powder compositions that had been irradiated retainedmost of their original free-flowing characteristics described above anddid not tend to fibrillate. Additionally, the quality of thePTFE/organoclay compositions (as observed in this qualitative rubbingtest) increased as the intensity of the irradiation increased from 7 to14 and finally to 28 megarads. Thus, the present Example shows that inembodiments where PTFE in its reactor latex form is chosen as thecharacteristic use particle, the PTFE/organoclay compositions formed maybe irradiated and exhibit good dispersibility in various target media.

Example 15 Preparation of Reactor Latex PTFE/Organoclay CompositionsUsing Laponite as the Clay

In this Example, PTFE in its reactor latex form was again used as thecharacteristic use particle, and organoclay was used as the physicalentrapment phase. A 60/40 organoclay/PTFE composition was preparedaccording to the detailed procedure in Example 12 above, except that theorganoclay/PTFE concentration was changed from 50/50 to 60/40 and theclay used in the present Example was Laponite rather than bentonite.Specifically, Laponite RD is a synthetic clay, commercially availablefrom Southern Clay Products, which generally has a smaller particle sizethan bentonite clay. The Clay/Quat ratios for the samples formed in thisExample varied from 1:0.3 to 1:1.5. Qualitative analyses were done, andit was determined that the optimal Clay/Quat ratio for Laponite clay is1:0.7. Generally, the reactor latex PTFE/organoclay compositions formedwith Laponite clay exhibited less stickiness than those formed with theother clays studied. Furthermore, because Laponite has a smallerparticle size relative to certain other clays, it was contemplated thatin embodiments where Laponite is the clay of choice, the concentrationof the organoclay (in relation to the concentration of PTFE) may besignificantly reduced. This is because the smaller particle size ofLaponite clay leads to the clay having a higher amount of exposedsurface area that is available to act as part of the physical entrapmentphase and that therefore keeps the characteristic use particlesdispersed in the target medium.

The results of Examples 12-15 show that PTFE in its reactor latex formmay be chosen as a characteristic use particle according to the methodof the present invention and may experience the benefits of beingentrapped in a physical entrapment phase, such as an organoclay. Thereactor latex PTFE generally experiences enhanced dispersibility invarious target media, such as organic systems, when it is combined withorganoclay as the physical entrapment phase, as contemplated by thepresent invention. Furthermore, the primary particle size of the PTFEparticles is retained as the reactor latex PTFE is incorporated into aphysical entrapment phase such as organoclay. Also, the organoclay/PTFEcompositions made using PTFE in its reactor latex form as thecharacteristic use particle generally exhibit low levels ofagglomeration when dispersed in various target media, exhibit low levelsof stickiness, and are free-flowing in nature.

1. A composition that is dispersible in a target medium, the compositioncomprising characteristic use particles entrapped within a physicalentrapment phase, wherein the characteristic use particles have nativesizes and native features, wherein the physical entrapment phase isdispersible in the target medium, and wherein when the composition isdispersed in the target medium a substantial number of the physicallyentrapped characteristic use particles are released from thecomposition, whereby the released characteristic use particles exhibitsubstantially their original native sizes and native features in thetarget medium.
 2. The composition of claim 1 wherein the physicalentrapment phase is formed by mixing a physical entrapment phaseprecursor with the characteristic use particles in a processing mediumin which the precursor is dispersible, wherein the precursor is thenconverted by reaction with a triggering agent into the physicalentrapment phase entrapping the characteristic use particles, andwherein the physical entrapment phase is not dispersible in theprocessing medium.
 3. The composition of claim 2 wherein the physicalentrapment phase having the characteristic use particles entrappedtherein is separated from the processing medium and wherein thecomposition is substantially free of the processing medium.
 4. Thecomposition according to claim 2, wherein said precursor issmectite-type clay and said triggering agent is an organic cation. 5.The composition according to claim 2, wherein said precursor is selectedfrom the group consisting of montmorillonite, bentonite, beidellite,hectorite, saponite, stevensite, and mixtures thereof; and said organiccation has a formula

wherein X is nitrogen or phosphorus, Y is sulfur, R1 is the long chain,linear or branched, saturated or unsaturated alkyl group and R2, R3 andR4 can be independently selected from the group consisting of linear orbranched alkyl groups having 1 to 22 carbon atoms; aralkyl groups whichare benzyl and substituted benzyl moieties including fused ring moietieshaving linear or branched 1 to 22 carbon atoms in the alkyl portion ofthe structure; aryl groups; beta, gamma-unsaturated groups having six orless carbon atoms or hydroxyalkyl groups having two to six carbon atoms;and hydrogen.
 6. The composition according to claim 2, wherein saidprecursor is metal salt and said triggering agent is selected from thegroup consisting of an acid and a base.
 7. The composition according toclaim 6, wherein said metal salt is a water soluble metal salt.
 8. Thecomposition according to claim 7, wherein said composition is furtherpeptized with dilute mineral acids.
 9. The composition according toclaim 1, wherein a dispersion of the composition in the target mediumhas a Hegman grind gauge improvement of greater than or equal to 1 unitcompared to the Hegman grind gauge value of a mixture of characteristicuse particles dispersed without the mediation of the physical entrapmentphase in the target medium.
 10. The composition according to claim 1,wherein a mixture of the composition has a 1 minute sieve weight %result of greater than or equal to about 10% in comparison to a 1 minutesieve weight % result of a sample of pure characteristic use particles.11. The composition according to claim 1, wherein the composition has aparticle size decrease of greater than or equal to about 10% incomparison to the particle size results of pure characteristic useparticles.
 12. The composition according to claim 1, wherein thephysical entrapment phase comprises a plurality of physical entrapmentparticles.
 13. The composition according to claim 12, wherein the numberratio of physical entrapment phase particles to characteristic useparticles is greater than or equal to about 1510:1.
 14. The compositionaccording to claim 1, wherein said characteristic use particles areselected from the group consisting of PTFE, PE, PPE, TiO₂, carbon black,CaCO₃, and mixtures thereof.
 15. The composition according to claim 1,wherein said characteristic use particle is selected from the groupconsisting of polymers having one or more monomers, resins, binders,metal oxides, pigments, extenders, dyes, film forming agents,anticorrosive agents, matting/flattening agents, rheological modifiers,biocides, inorganic fillers, flow modifiers, and mixtures thereof; andwherein said physical entrapment phase particles are selected from thegroup consisting of organoclays, hydrous oxides, SiO₂, organic salts,acrylic polymers, and mixtures thereof.
 16. The composition according toclaim 1, wherein said characteristic use particle is selected from thegroup consisting of polytetrafluoroethylene (PTFE), polyethylene (PE),polypropylene (PPE), polyethylene terephthalate (PET), polystyrene,polycarbonate, polymethyl methacrylates, polybutadiene, titanium dioxide(TiO2), magnesium oxide (MgO), zinc oxide (ZnO), ferrous oxide (FeO),ferric oxide (Fe2O3), calcium carbonate (CaCO3), lead chromate (PbCrO4),barium sulfate (BaSO4), molybdate orange, hansa yellow, phthalocyanineblue, phthalocyanine green, carbazole violet, carbon black, rubininered, talc, china clay, mica, feldspar, waxes, and mixtures thereof; andwherein said physical entrapment phase particles are selected from thegroup consisting of organoclay and hydrous oxides.
 17. The compositionof claim 1 wherein said characteristic use particle is a submicronparticle.
 18. The composition of claim 1 wherein said characteristic useparticle is PTFE in its reactor latex form.
 19. A composition comprisingA. a target medium; B. characteristic use particles dispersed within thetarget medium; and C. a physical entrapment phase dispersed within thetarget medium, wherein the composition has a grind gauge improvement ofgreater than or equal to 1 unit in comparison to the grind gauge for thecomposition without the physical entrapment phase.
 20. The compositionaccording to claim 19, wherein the physical entrapment phase comprises aplurality of physical entrapment particles.
 21. The compositionaccording to claim 20, wherein the number ratio of physical entrapmentphase particles to characteristic use particles is greater than or equalto about 10:1.
 22. The composition according to claim 19, wherein saidtarget medium is selected from the group consisting of hydrophobictarget media and hydrophillic target media; wherein said characteristicuse particle is selected from the group consisting of polymers havingone or more monomers, resins, binders, metal oxides, pigments,extenders, dyes, film forming agents, anticorrosive agents,matting/flattening agents, rheological modifiers, biocides, inorganicfillers, flow modifiers, and mixtures thereof; and wherein said physicalentrapment phase particles are selected from the group consisting oforganoclays, hydrous oxides, SiO₂, organic salts, acrylic polymers, andmixtures thereof.
 23. The composition according to claim 19, whereinsaid target medium is selected from the group consisting ofhydrocarbon-based compositions, solvents, unsaturated hydrocarbons,formamides, acetones of C6 or higher carbon content, alcohols withcarbon chain lengths of C5 or higher, resins, fillers, film formers,coatings, inks, polymers, chloro, fluoro and nitro solvents, water ofneutral, acidic, or basic pH, linear and branched C1 to C4 alcohols, C1to C4 glycols, organic acids and their alkali metal salts, ionic fluidscontaining water and water soluble electrolytes, C1 to C3 amines, andlow molecular weight organic sulfonic acids and their salts; saidcharacteristic use particle is selected from the group consisting ofpolytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PPE),polyethylene terephthalate (PET), polystyrene, polycarbonate, polymethylmethacrylates, polybutadiene, titanium dioxide (TiO₂), magnesium oxide(MgO), zinc oxide (ZnO), ferrous oxide (FeO), ferric oxide (Fe₂O₃),calcium carbonate (CaCO₃), lead chromate (PbCrO₄), barium sulfate(BaSO₄), molybdate orange, hansa yellow, phthalocyanine blue,phthalocyanine green, carbazole violet, carbon black, rubinine red,talc, china clay, mica, feldspar, waxes, and mixtures thereof; and saidphysical entrapment phase particles are selected from the groupconsisting of organoclay and hydrous oxides.
 24. The compositionaccording to claim 19, wherein said characteristic use particles areselected from the group consisting of PTFE, PE, PPE, TiO₂, carbon black,CaCO₃, and mixtures thereof.
 25. The composition according to claim 19,wherein said characteristic use particle is a submicron particle. 26.The composition according to claim 19, wherein said characteristic useparticle is PTFE in its reactor latex form.